HistoricalChristian.Faith

Deuteronomy 6

1 Now these are the commandments, the statutes, and the judgments, which the LORD your God commanded to teach you, that ye might do them in the land whither ye go to possess it: 2 That thou mightest fear the LORD thy God, to keep all his statutes and his commandments, which I command thee, thou, and thy son, and thy son's son, all the days of thy life; and that thy days may be prolonged. 3 Hear therefore, O Israel, and observe to do it; that it may be well with thee, and that ye may increase mightily, as the LORD God of thy fathers hath promised thee, in the land that floweth with milk and honey. 4 Hear, O Israel: The LORD our God is one LORD: 5 And thou shalt love the LORD thy God with all thine heart, and with all thy soul, and with all thy might. 6 And these words, which I command thee this day, shall be in thine heart: 7 And thou shalt teach them diligently unto thy children, and shalt talk of them when thou sittest in thine house, and when thou walkest by the way, and when thou liest down, and when thou risest up. 8 And thou shalt bind them for a sign upon thine hand, and they shall be as frontlets between thine eyes. 9 And thou shalt write them upon the posts of thy house, and on thy gates. 10 And it shall be, when the LORD thy God shall have brought thee into the land which he sware unto thy fathers, to Abraham, to Isaac, and to Jacob, to give thee great and goodly cities, which thou buildedst not, 11 And houses full of all good things, which thou filledst not, and wells digged, which thou diggedst not, vineyards and olive trees, which thou plantedst not; when thou shalt have eaten and be full; 12 Then beware lest thou forget the LORD, which brought thee forth out of the land of Egypt, from the house of bondage. 13 Thou shalt fear the LORD thy God, and serve him, and shalt swear by his name. 14 Ye shall not go after other gods, of the gods of the people which are round about you; 15 (For the LORD thy God is a jealous God among you) lest the anger of the LORD thy God be kindled against thee, and destroy thee from off the face of the earth. 16 Ye shall not tempt the LORD your God, as ye tempted him in Massah. 17 Ye shall diligently keep the commandments of the LORD your God, and his testimonies, and his statutes, which he hath commanded thee. 18 And thou shalt do that which is right and good in the sight of the LORD: that it may be well with thee, and that thou mayest go in and possess the good land which the LORD sware unto thy fathers, 19 To cast out all thine enemies from before thee, as the LORD hath spoken. 20 And when thy son asketh thee in time to come, saying, What mean the testimonies, and the statutes, and the judgments, which the LORD our God hath commanded you? 21 Then thou shalt say unto thy son, We were Pharaoh's bondmen in Egypt; and the LORD brought us out of Egypt with a mighty hand: 22 And the LORD shewed signs and wonders, great and sore, upon Egypt, upon Pharaoh, and upon all his household, before our eyes: 23 And he brought us out from thence, that he might bring us in, to give us the land which he sware unto our fathers. 24 And the LORD commanded us to do all these statutes, to fear the LORD our God, for our good always, that he might preserve us alive, as it is at this day. 25 And it shall be our righteousness, if we observe to do all these commandments before the LORD our God, as he hath commanded us.
Commentaries
Markon Deuteronomy 6:5AD 60
And one of the scribes came, and having heard them reasoning together, and perceiving that he had answered them well, asked him, Which is the first commandment of all? And Jesus answered him, The first of all the commandments is, Hear, O Israel; The Lord our God is one Lord: And thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind, and with all thy strength: this is the first commandment. [Deuteronomy 6:5] And the second is like, namely this, Thou shalt love thy neighbour as thyself. There is none other commandment greater than these. And the scribe said unto him, Well, Master, thou hast said the truth: for there is one God; and there is none other but he: And to love him with all the heart, and with all the understanding, and with all the soul, and with all the strength, and to love his neighbour as himself, is more than all whole burnt offerings and sacrifices. And when Jesus saw that he answered discreetly, he said unto him, Thou art not far from the kingdom of God. And no man after that durst ask him any question.
Markon Deuteronomy 6:4AD 60
And one of the scribes came, and having heard them reasoning together, and perceiving that he had answered them well, asked him, Which is the first commandment of all? And Jesus answered him, The first of all the commandments is, Hear, O Israel; The Lord our God is one Lord: [Deuteronomy 6:4] And thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind, and with all thy strength: this is the first commandment. And the second is like, namely this, Thou shalt love thy neighbour as thyself. There is none other commandment greater than these. And the scribe said unto him, Well, Master, thou hast said the truth: for there is one God; and there is none other but he: And to love him with all the heart, and with all the understanding, and with all the soul, and with all the strength, and to love his neighbour as himself, is more than all whole burnt offerings and sacrifices. And when Jesus saw that he answered discreetly, he said unto him, Thou art not far from the kingdom of God. And no man after that durst ask him any question.
Matthewon Deuteronomy 6:13AD 60
Again, the devil taketh him up into an exceeding high mountain, and showeth him all the kingdoms of the world, and the glory of them; And saith unto him, All these things will I give thee, if thou wilt fall down and worship me. Then saith Jesus unto him, Get thee hence, Satan: for it is written, Thou shalt worship the Lord thy God, and him only shalt thou serve. [Deuteronomy 6:13] Then the devil leaveth him, and, behold, angels came and ministered unto him.
Matthewon Deuteronomy 6:5AD 60
But when the Pharisees had heard that he had put the Sadducees to silence, they were gathered together. Then one of them, which was a lawyer, asked him a question, tempting him, and saying, Master, which is the great commandment in the law? Jesus said unto him, Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind. [Deuteronomy 6:5] This is the first and great commandment. And the second is like unto it, Thou shalt love thy neighbour as thyself. On these two commandments hang all the law and the prophets.
Matthewon Deuteronomy 6:16AD 60
Then the devil taketh him up into the holy city, and setteth him on a pinnacle of the temple, And saith unto him, If thou be the Son of God, cast thyself down: for it is written, He shall give his angels charge concerning thee: and in their hands they shall bear thee up, lest at any time thou dash thy foot against a stone. Jesus said unto him, It is written again, Thou shalt not tempt the Lord thy God. [Deuteronomy 6:16]
Lukeon Deuteronomy 6:13AD 61
And the devil, taking him up into an high mountain, showed unto him all the kingdoms of the world in a moment of time. And the devil said unto him, All this power will I give thee, and the glory of them: for that is delivered unto me; and to whomsoever I will I give it. If thou therefore wilt worship me, all shall be thine. And Jesus answered and said unto him, Get thee behind me, Satan: for it is written, Thou shalt worship the Lord thy God, and him only shalt thou serve. [Deuteronomy 6:13]
Lukeon Deuteronomy 6:5AD 61
And, behold, a certain lawyer stood up, and tempted him, saying, Master, what shall I do to inherit eternal life? He said unto him, What is written in the law? how readest thou? And he answering said, Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy strength, and with all thy mind; and thy neighbour as thyself. [Deuteronomy 6:5] And he said unto him, Thou hast answered right: this do, and thou shalt live. But he, willing to justify himself, said unto Jesus, And who is my neighbour? And Jesus answering said, A certain man went down from Jerusalem to Jericho, and fell among thieves, which stripped him of his raiment, and wounded him, and departed, leaving him half dead. And by chance there came down a certain priest that way: and when he saw him, he passed by on the other side. And likewise a Levite, when he was at the place, came and looked on him, and passed by on the other side. But a certain Samaritan, as he journeyed, came where he was: and when he saw him, he had compassion on him, And went to him, and bound up his wounds, pouring in oil and wine, and set him on his own beast, and brought him to an inn, and took care of him. And on the morrow when he departed, he took out two pence, and gave them to the host, and said unto him, Take care of him; and whatsoever thou spendest more, when I come again, I will repay thee. Which now of these three, thinkest thou, was neighbour unto him that fell among the thieves? And he said, He that showed mercy on him. Then said Jesus unto him, Go, and do thou likewise.
Lukeon Deuteronomy 6:16AD 61
And he brought him to Jerusalem, and set him on a pinnacle of the temple, and said unto him, If thou be the Son of God, cast thyself down from hence: For it is written, He shall give his angels charge over thee, to keep thee: And in their hands they shall bear thee up, lest at any time thou dash thy foot against a stone. And Jesus answering said unto him, It is said, Thou shalt not tempt the Lord thy God. [Deuteronomy 6:16] And when the devil had ended all the temptation, he departed from him for a season.
Origen of Alexandriaon Deuteronomy 6:5AD 253
The great and first commandment in the law, therefore, is this: You shall love the Lord your God with your whole heart and with your whole soul and with your whole mind. But whoever subtracts anything from that whole commandment — that is, either from what it says with your whole heart or with your whole soul or with your whole mind — subtracts from its magnitude and from its primacy. And perhaps all who love their Lord God, unless they also fulfill the parts that follow and love him with their whole heart and with their whole soul and with their whole mind, keep the commandment only in part; but those alone take up its magnitude and primacy within themselves who not only love their Lord God but have also taken up those three — that is, so that with their whole heart they store up within themselves that whole one and his works and his thoughts, and with their whole soul, that is, so that they are ready to lay it down for the piety of God who created all things, when the usefulness of the word demands it, out of the fact that with the whole soul one loves God, in such a way that no part of the soul is torn away toward any thing that is foreign to the faith, and in our whole mind thinking or bringing forth nothing else but "the things that are of God". And see whether you can take heart to mean the intellect, which gazes upon intelligible things and shows the source and beginning of them, which is God, and mind to mean the bringing forth of things (for it is with the mind that we bring forth individual things, and through each thing that is signified we walk about, as it were, with our mind and bring it forth). And if anyone should understand ingeniously the commandment which was laid down concerning love in all those three things that have been named, and should consider in each of the several faithful the love of God, he will perhaps find the whole commandment either in one, or perhaps the second or the third (and this if it should be granted), but in all of them the love of God having less — whether a little or more — either from what it says with your whole heart or from what it says with your whole soul or with your whole mind.
Origen of Alexandriaon Deuteronomy 6:5AD 253
Something of this kind is shown also concerning the commandment of love toward God and toward the neighbor, when it says thus: "You shall love the Lord your God with your whole heart and with your whole soul and with your whole strength". For without doubt, when anyone shall have loved God "with his whole heart" "and with his whole soul" "and with his whole strength", he has such a reward of love as the one who had a greater heart, or who has a more eminent soul, or who received greater strength. For this alone is sought, that whatever a man may have from God, he should use the whole of it for the glory of God.
Origen of Alexandriaon Deuteronomy 6:5AD 253
Whatever each one worships above the rest, whatever he admires and loves above all things, this is his God. Indeed, this is what before all things and above all things God demands of man by his commandment: "you shall love", he says, "the Lord your God with all your heart and with all your soul and with all your strength" — desiring in a manner to lay first claim to himself upon all the affections of the human mind, and knowing that whatever one "loves with all the heart and with all the soul and with all the strength", this is his God. Let each one now examine himself and silently reckon up from his own heart what flame of love above all else and beyond all things burns hottest in him, what affection is cherished in him more ardent than the rest. Do you yourselves hold judgment concerning these things, weigh them on the balance of your own examination, and if there be anything that outweighs in the scale of love, this is your God. But I fear that in very many the love of gold outweighs, and that the weight of avarice, pressing the scale down enough, sinks it. And to such a one it will surely be said: "you cannot serve God and mammon" — that is, avarice.
Origen of Alexandriaon Deuteronomy 6:8AD 253
It must be understood in these matters that it is written in the law concerning the divine words, saying: "bind them upon your hand, and they shall be moving before your eyes". Those, therefore, who do all things in order to be seen by men, the scribes and Pharisees, writing certain sayings of the law on two cut pieces of parchment, bind them, and one indeed they carry on their houses, as it were placing upon their heads as a crown that which is written according to the forehead. But the other upon the arm of their hand; and they call them "phylacteries". Similarly, finding something also about the fringe in Deuteronomy, they suppose that they keep the law by making some fringe on some part of the garments which they wear.

But the disciples of Jesus do all their works in order to be seen by God alone; for they bind the law of God upon their hand, spiritually upon their good work, and by meditation on the divine teachings, ever moving them, they make the divine precepts moving before the eyes of their souls, and the fringe full of the virtue of Jesus — in this, that they imitate the Master.
Hilary of Poitierson Deuteronomy 6:4AD 367
And now let us see whether the confession of Thomas the Apostle, when he cried, My Lord and My God, corresponds with this assertion of the Evangelist. We see that he speaks of Him, Whom he confesses to be God, as My God. Now Thomas was undoubtedly familiar with those words of the Lord, Hear, O Israel, the Lord thy God is One. How then could the faith of an Apostle become so oblivious of that primary command as to confess Christ as God, when life is conditional upon the confession of the Divine unity? It was because, in the light of the Resurrection, the whole mystery of the faith had become visible to the Apostle. He had often heard such words as, I and the Father are One, and, All things that the Father hath are Mine, and, I in the Father and the Father in Me; and now he can confess that the name of God expresses the nature of Christ, without peril to the faith. Without breach of loyalty to the One God, the Father, his devotion could now regard the Son of God as God, since he believed that everything contained in the nature of the Son was truly of the same nature with the Father. No longer need he fear that such a confession as his was the proclamation of a second God, a treason against the unity of the Divine nature; for it was not a second God Whom that perfect birth of the Godhead had brought into being. Thus it was with full knowledge of the mystery of the Gospel that Thomas confessed his Lord and his God. It was not a title of honour; it was a confession of nature. He believed that Christ was God in substance and in power.
Gregory of Nyssaon Deuteronomy 6:5AD 395
If one does not love God with all his heart and with all his soul, how can he care wholesomely and guilelessly for the love of his brothers, since he is not fulfilling the love of the One on whose account he has a care for the love of his brothers? The person in this condition, who has not given his whole soul to God and has not participated in his love, the craftsman of evil finds disarmed and easily overpowers. .
Gregory of Nyssaon Deuteronomy 6:4AD 395
This is the cause why it says, "the Lord our God is one Lord," and also proclaims the Only-begotten God by the name of Godhead, without dividing the Unity into a dual signification, so as to call the Father and the Son two Gods, although each is proclaimed by the holy writers as God. The Father is God: the Son is God: and yet by the same proclamation God is One, because no difference either of nature or of operation is contemplated in the Godhead. For if (according to the idea of those who have been led astray) the nature of the Holy Trinity were diverse, the number would by consequence be extended to a plurality of Gods, being divided according to the diversity of essence in the subjects. But since the Divine, single, and unchanging nature, that it may be one, rejects all diversity in essence, it does not admit in its own case the signification of multitude; but as it is called one nature, so it is called in the singular by all its other names, "God," "Good," "Holy," "Saviour," "Just," "Judge," and every other Divine name conceivable.
Ambrose of Milanon Deuteronomy 6:5AD 397
He says, 'Let the earth bring forth green herb,' and immediately the whole earth, at the rising of the germ, is filled with all kinds of plants. And to man it is said: 'Love the Lord your God' (Deut., VI, 5), and the love of God is not infused into the hearts of all. The hearts of men are more deaf than the hardest rocks. The earth produces fruits for us undeservedly, while obeying its creator; we deny the debt of gratitude, while not honoring the creator.
Ambrose of Milanon Deuteronomy 6:5AD 397
And therefore it is written, Thou shalt love the Lord thy God. Now he who loves also believes, and in believing each man begins to love. Abraham believed, and so began to love, and he believed not in part, but entirely. For otherwise he would not have perfect charity, for it is written, Charity believeth all things. If it believe not all things, charity does not seem to be perfect. Perfect charity then has all faith.
Ambrose of Milanon Deuteronomy 6:5AD 397
And the law says: "Thou shalt love the Lord thy God, thou shalt love thy neighbour." It is a noble thing to do one's kindnesses and duties towards the whole of the human race. But it is ever most seemly that thou shouldst give to God the most precious thing thou hast, that is, thy mind, for thou hast nothing better than that. When thou hast paid thy debt to thy Creator, then thou mayest labour for men, to show them kindness, and to give help; then thou mayest assist the needy with money, or by some duty, or some service that lies in the way of thy ministry; by money to support him; by paying a debt, so as to free him that is bound; by undertaking a duty, so as to take charge of a trust, which he fears to lose, who has put it by in trust.
Ambrose of Milanon Deuteronomy 6:4AD 397
The law says, "Hear, O Israel, the Lord your God." It did not say "speak" but "hear." Eve fell because she said to the man what she had not heard from the Lord her God. The first word from God says to you, "hear."
Ambrose of Milanon Deuteronomy 6:4AD 397
Such too was the teaching of the law: "Hear, O Israel, the Lord your God is one Lord," that is, unchangeable, always abiding in unity of power, always the same and not altered by any accession or diminution. Therefore Moses called him one.
John Chrysostomon Deuteronomy 6:4AD 407
"What then?" one may say, "were they wronged, who lived before His coming?" By no means, for men might then be saved, even though they had not confessed Christ. For this was not required of them, but not to worship idols, and to know the true God. "For the Lord thy God," it is said, "is one Lord." Therefore the Maccabees were admired, because for the observance of the law they suffered what they did suffer; and the three children, and many others too amongst the Jews, having shown forth a very virtuous life, and having maintained the standard of this their knowledge, had nothing more required of them. For then it was sufficient for salvation, as I have said already, to know God only; but now it is so no more, but there is need also of the knowledge of Christ. Therefore He said, "If I had not come and spoken unto them, they had not had sin, but now they have no cloak for their sin."
Augustine of Hippoon Deuteronomy 6:13AD 430
What is to be said of justice in its relation to God? As the Lord says, "No man can serve two masters," and the apostle rebukes those who serve the creature rather than the Creator, so had it not been said before in the Old Testament: "You shall adore the Lord your God and him only shall you serve"? But what need is there to say more about this here since the Scriptures are full of such texts? Justice then offers this rule of life to the lover we are describing: that he serve with gladness the Lord whom he loves, that is to say, the supreme good, the supreme wisdom, the supreme peace; and with respect to all other things, that he govern those which are subject to him and endeavor to subject all else to the same rule. This rule of life is confirmed, as we have shown, by the authority of both Testaments.
Source: ON THE CATHOLIC AND THE MANICHAEAN WAYS OF LIFE 1.24.44
Augustine of Hippoon Deuteronomy 6:13AD 430
Whoever yields assent to the supreme authority of divine Scripture should first examine these words: "The Lord your God shall you adore, and him only shall you serve." In Greek the expression used does not signify the service owed to human masters but that which is offered to God, called latreia. Thus idolatry is rightly condemned because the latreia which is due to the true God alone is offered to idols. It does not say, "You shall adore only the Lord your God," but it says, "And him only shall you serve." It used the word only with "you shall serve," meaning, no doubt, that service which is called latreia. To this service belong temple, sacrifice, priest, and other like attributes.
Source: LETTER 173A
Augustine of Hippoon Deuteronomy 6:5AD 430
Therefore the supreme and true wisdom is in that first commandment: "You shall love the Lord your God with your whole heart and with your whole soul." From this it follows that wisdom is love of God, which is "poured forth in our hearts," not otherwise than "by the Holy Spirit who is given to us." But "the fear of the Lord is the beginning of wisdom," and "there is no fear in love, but perfect love casts out fear."
Augustine of Hippoon Deuteronomy 6:5AD 430
Now it is plain that the number four has relation to the body, from the four well known elements of which it consists, and the four qualities of dry, humid, warm, cold. Hence too it is administered by four seasons, spring, summer, autumn, winter. All this is very well known. For of the number four relating to the body we have treated elsewhere somewhat subtilly, but obscurely: which must be avoided in this discourse, which we would have accommodated to the unlearned. But that the number three has relation to the mind may be understood from this, that we are commanded to love God after a threefold manner, with the whole heart, with the whole soul, with the whole mind: of each of which severally we must treat, not in the Psalms, but in the Gospels: for the present, for proof of the relation of the number three to the mind, I think what has been said enough.
Augustine of Hippoon Deuteronomy 6:5AD 430
Then in all this plenitude of charity will be fulfilled the commandment, "Thou shalt love the Lord thy God with all thine heart, and with all thy soul, and with all thy mind." For while there remains any remnant of the lust of the flesh, to be kept in check by the rein of continence, God is by no means loved with all one's soul. For the flesh does not lust without the soul; although it is the flesh which is said to lust, because the soul lusts carnally. In that perfect state the just man shall live absolutely without any sin, since there will be in his members no law warring against the law of his mind, but wholly will he love God, with all his heart, with all his soul, and with all his mind which is the first and chief commandment.
Augustine of Hippoon Deuteronomy 6:4AD 430
That Trinity is one God. Not that Father, Son and Holy Spirit are identically the same. But the Father is Father, the Son is Son, and the Holy Spirit is Holy Spirit, and this Trinity is one God, as it is written: "Hear, O Israel, the Lord your God is one God."
Augustine of Hippoon Deuteronomy 6:4AD 430
Consider now for a while the passages of Scripture which force us to confess that the Lord is one God, whether we are asked about the Father alone, or the Son alone, or the Holy Spirit alone, or about the Father and the Son and the Holy Spirit together. Certainly it is written, "Hear, O Israel, the Lord your God is one Lord." Of whom do you think that this is said? If it is said only of the Father, then our Lord Jesus Christ is not God. Why did those words come to Thomas when he touched Christ and cried out, "My Lord and my God," which Christ did not reprove but approved, saying, "Because you have seen, you have believed"?
Source: LETTER 238
Desert Fatherson Deuteronomy 6:5AD 500
Somebody asked Antony, 'What shall I do in order to please God?' He replied, 'Do what I tell you, which is this: wherever you go, keep God in mind; whatever you do, follow the example of holy Scripture; wherever you are, stay there and do not move away in a hurry. If you keep to these guide-lines, you will be saved.'
Philoxenus of Mabbugon Deuteronomy 6:12AD 523
Observe then these defects, O thou that lovest spiritual excellence, and excuse thyself from this wickedness, that thou mayest not forget God and thine own self thereby, and thy discernment be darkened against all that is seemly; and with these remember also that which was spoken by the prophet Moses to the Jews, saying, "Take heed when thou eatest, and art satisfied, lest thou forget the Lord thy God who brought thee forth out of the land of Egypt." And behold the Spirit of God hath taught thee openly that error is born of fulness of food, and that, when a man hath forgotten God, he marcheth fearlessly into all wickedness, and associateth himself with all evils. For as the sight of a stern master is to riotous slaves, even so is the remembrance of God unto the soul; for it maketh the tumultuousness of the thoughts shamefaced, and immediately the thought of Him falleth into the mind all the perturbed thoughts hasten to put themselves in the order of fear, and the soul becometh suddenly a peaceful house, an ordered temple, a pure dwelling, and a holy mansion of the Trinity.
Philoxenus of Mabbugon Deuteronomy 6:5AD 523
That the people should love God was the greatest of the commandments, and therefore Moses urged them to fear Him. The commandment, "[Thou shalt] love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind", belonged to those who were righteous among them; but those who were like slaves, and who like slaves were committing offences at all times, he commanded to fear God, for fear repulseth vices, and love perfecteth virtues. Fear cutteth off the path of iniquitous men, and love urgeth on the way of the virtues. "Fear God", and "Love the Lord thy God"; these two commands were ordained in the law which was given to the people, so that whosoever became exalted above the command of fear might find before him the command of love, which is perfected therefrom.
Fulgentius of Ruspeon Deuteronomy 6:4AD 533
Therefore, in whatever place you may be, because you know that you have been baptized in the one name of the Father and the Son and the Holy Spirit, according to the rule promulgated by the command of our Savior, retain this rule with your whole heart, from the start and without hesitation: the Father is God, and the Son is God, and the Holy Spirit is God. This means the holy and ineffable Trinity is by nature one God, concerning whom it is said in Deuteronomy, "Hear, O Israel, the Lord your God is one God," and "You shall adore the Lord your God and him alone shall you serve." Indeed, … we have said that this one God who alone is true God by nature, is not the Father only, nor the Son only, nor the Holy Spirit only but is at one and the same time Father, Son and Holy Spirit. [Thus] we must be wary that while we say in truth that as the Father, Son, and Holy Spirit are one God, insofar as this is a unity of nature, we dare not say or believe something altogether blasphemous. [Such a blasphemous saying would be] that he who is the person of the Father is the same as either the Son or the Holy Spirit, or that he who is the person of the Son is the Father or the Holy Spirit. Or [it might be] that we dare to say or to believe that the person who is properly called the Holy Spirit in the confession of this Trinity is either the Father or the Son, something that is altogether wicked.
Source: TO PETER ON THE FAITH 1.3
Cassiodoruson Deuteronomy 6:5AD 585
As the law teaches, "You shall love the Lord your God with your whole heart and your whole soul." But the person who puts his entire hope in the Lord also praises with his whole heart. He does not put his trust in the transient consolations of the world, once he has trained himself on the Lord with total purity of mind.
Source: EXPOSITION OF THE PSALMS 85:12
Bernard of Clairvauxon Deuteronomy 6:5AD 1153
See for yourself if those three commands are not prescribed in the law when God says: "You shall love the Lord your God with your whole heart, your whole soul and your whole strength." It seems to me, if no more suitable meaning for this triple distinction comes to mind, that the love of the heart relates to a certain warmth of affection, the love of the soul to energy or judgment of reason, and the love of strength can refer to constancy and vigor of spirit. So love the Lord your God with the full and deep affection of your heart, love him with your mind wholly awake and discreet, love him with all your strength, so much so that you would not even fear to die for love of him. Your affection for your Lord Jesus should be both tender and intimate, to oppose the sweet enticements of sensual life. Sweetness conquers sweetness as one nail drives out another. No less than this keep him as a strong light for your mind and a guide for your intellect, not only to avoid the deceits of heresy and to preserve the purity of your faith from their seductions, but also that you might carefully avoid an indiscreet and excessive vehemence in your conversation. Let your love be strong and constant, neither yielding to fear nor cowering at hard work. Let us love affectionately, discreetly, intensely. We know that the love of the heart, which we have said is affectionate, is sweet indeed, but liable to be led astray if it lacks the love of the soul. And the love of the soul is wise indeed, but fragile without that love which is called the love of strength.

So then, to love with your whole heart, your whole soul and your whole strength means not being led astray by allurements, or seduced by lies, or broken by injuries.
Bonaventureon Deuteronomy 6:4AD 1257
The Jews sometimes reproach us and say that we do not properly observe the first commandment. Concerning the first statement, namely: "You shall not have strange gods," they say that the Lord says: "Hear, O Israel, the Lord your God is one;" and you posit a Trinity, namely the Father and the Son and the Holy Spirit.

To this objection, that we worship three gods, I say that if we worshipped three persons such that we said there were three gods and a threefold essence, it would necessarily follow that we worshipped three gods. But we worship the Father and the Son and the Holy Spirit, one God and one essence, but three persons. Whence, just as we see that in man there is a plurality of natures, namely intellectual and corporeal, and yet there is but one person, so conversely in the divine there is unity of essence and plurality of persons.

God the Father has a Word and the Holy Spirit: indeed He has a Word, through which He made all things; and He has the Holy Spirit, through whom He preserves all things. The Word flows forth from the one who speaks and is God from God. Likewise the Holy Spirit is spirated from the Father and the Son and is God and in God. The Holy Spirit alone is the one who searches the depths of hearts, and He is God.

Hence the person who wishes to understand these things and to speak about them must have the most elevated thoughts, not earthbound ones: for otherwise he cannot understand the most exalted things concerning God. For when we posit the Trinity, we do not posit Christ as a mere man, but God with man.
Bonaventureon Deuteronomy 6:4AD 1257
And these things are so certain that the opposite of them cannot be thought by one understanding being itself, and one of them necessarily implies the other. For because it is simply being, therefore it is simply first: because it is simply first, therefore it is not made by another, nor could it have been made by itself, therefore it is eternal. Likewise, because it is first and eternal; therefore it is not from others, therefore it is most simple. Likewise, because it is first, eternal, and most simple: therefore there is nothing of potentiality mixed with act in it, and therefore it is most actual. Likewise, because it is first, eternal, most simple, most actual; therefore it is most perfect: to such a being absolutely nothing is lacking, nor can any addition be made. Because it is first, eternal, most simple, most actual, most perfect: therefore it is supremely one. For what is said through every manner of superabundance with respect to all things. "What also is said simply through superabundance, it is impossible that it should belong to any but one alone." Whence if God names being primary, eternal, most simple, most actual, most perfect: it is impossible for him to be thought not to be, nor to be anything but one alone. Hear therefore, O Israel, your God is one God. If you see this in the pure simplicity of the mind, you will be in some measure flooded with the illumination of eternal light.
Bonaventureon Deuteronomy 6:4AD 1257
To the objection that if we are bound to believe this, it is either because it is true, or because it is a truth falling under a precept, it must be said that it is because it is a truth falling under a precept. And if you ask: under which precept? I say that under the first, in which indeed it is said: Hear, O Israel, the Lord your God is one God. You shall adore the Lord your God and Him alone shall you serve. In this precept indeed we are obligated expressly to believe that God is one, but implicitly to believe that God is triune. And this is evident as follows: because by this precept we are bound to worship God with the worship of latria, which is there called service. Now to worship in spiritual matters is according to a transumption from material things: in material things, however, to cultivate a field is to bring forth the shoots proceeding originally from the earth itself. In this same manner, to worship God is to profess by heart and mouth and deed that He is the principle, such that He is not perfectly worshipped unless we confess that He is the principiating principle not only effective in creation, but also restorative in redemption and perfective in glorification: nor yet perfectly, if He is believed to be a principle from time, unless He is believed to be a principiating principle from eternity: nor yet, unless He is believed to be a principle principiating one who eternally principiates: which we believe when we believe that the Father eternally generates the Son, who together with Him spirates the Holy Spirit, so that eternally in God there is a principle from a principle, and a principle not from a principle.