1 I will praise thee with my whole heart: before the gods will I sing praise unto thee. 2 I will worship toward thy holy temple, and praise thy name for thy lovingkindness and for thy truth: for thou hast magnified thy word above all thy name. 3 In the day when I cried thou answeredst me, and strengthenedst me with strength in my soul. 4 All the kings of the earth shall praise thee, O LORD, when they hear the words of thy mouth. 5 Yea, they shall sing in the ways of the LORD: for great is the glory of the LORD. 6 Though the LORD be high, yet hath he respect unto the lowly: but the proud he knoweth afar off. 7 Though I walk in the midst of trouble, thou wilt revive me: thou shalt stretch forth thine hand against the wrath of mine enemies, and thy right hand shall save me. 8 The LORD will perfect that which concerneth me: thy mercy, O LORD, endureth for ever: forsake not the works of thine own hands.
[AD 420] Jerome on Psalms 138:1
“I will confess to you, Lord, with all my heart.” The nature of a wound determines the medication to be applied. Just as the body has wounds of various kinds, so also the soul has its passions and its wounds, and we must do penance in proportion to the nature of our sin. If a person makes confession of all his sins, he is acknowledging his sins to the Lord wholeheartedly. If, for example, someone has committed fornication and he confesses only that and is greedy, or quick-tempered, or a slanderer or blasphemer and is full of faults and vices, his confession is not sincere. The person who repents for all the sins and passions of his soul is the person who is able to say, I confess and give thanks to you, O Lord, with all my heart. “For you have heard the words of my mouth.” This verse is not found in the Hebrew text. Nonetheless, what it means is, In my confession I have poured out my whole heart, O Lord; I have confessed all my sins and faults, for I have not admitted merely one sin to you, and you have listened to me graciously.

[AD 430] Augustine of Hippo on Psalms 138:1
The title of this Psalm is brief and simple, and need not detain us; since we know whose resemblance David wore, and since in him we recognise ourselves also, for we too are members of that Body. The whole title is, "To David himself." Let us see then, what is to David himself. The title of the Psalm is wont to tell us what is treated of within it: but in this, since the title informs us not of this, but tells us only to Whom it is chanted, the first verse tells us what is treated of in the whole Psalm, "I will confess to You." This confession then let us hear. But first I remind you, that the term confession in Scripture, when we speak of confession to God, is used in two senses, of sin, and of praise. But confession of sin all know, confession of praise few attend to. So well known is confession of sin, that, wherever in Scripture we hear the words, "I will confess to You, O Lord," or, "we will confess to You," immediately, through habitually understanding in this way, our hands hurry to beating our breast: so entirely are men wont not to understand confession to be of anything, save of sin. But was then our Lord Jesus Christ Himself too a sinner, who says in the Gospel, "I confess to You, Father, Lord of heaven and earth"? He goes on to say what He confesses, that we might understand His confession to be of praise, not of sin, "I confess to You, Father, Lord of heaven and earth, because You have hid these things from the wise and prudent, and hast revealed them unto babes." He praised the Father, he praised God, because He despises not the humble, but the proud. And such confession are we now going to hear, of praise of God, of thanksgiving. "With my whole heart." My whole heart I lay upon the altar of Your praise, an whole burnt-offering of praise I offer to You...."I will confess to You, O Lord, with my whole heart: for You have heard the words of my mouth" [Psalm 138:1]. What mouth, save my heart? For there have we the voice which God hears, which ear of man knows not at all. We have then a mouth within, there do we ask, thence do we ask, and if we have prepared a lodging or an house for God, there do we speak, there are we heard. "For He is not far from every one of us, for in Him we live, and move, and have our being." [Acts 17:27-28] Nought makes you far off from God, save sin only. Cast down the middle wall of sin, and you are with Him whom you ask.

[AD 735] Bede on Psalms 138:1
It is no secret that angels are frequently present, invisibly, at the side of the elect, in order to defend them from the snares of the cunning enemy and uphold them by the great gift of heavenly desire. The apostle attests to this when he says, “Are they not all ministering spirits sent to serve on account of those who receive an inheritance of salvation?” Nevertheless, we should believe that the angelic spirits are especially present to us when we give ourselves in a special way to divine services, that is, when we enter a church and open our ears to sacred reading, or give our attention to psalm singing, or apply ourselves to prayer or celebrate the solemnity of the mass. Hence the apostle advises women to have a veil over their heads in church on account of the angels. And a prophet says, “I will sing psalms to you in the sight of the angels.” We are not permitted to doubt that where the mysteries of the Lord’s body and blood are being enacted, a gathering of the citizens from on high is present—those who were keeping such careful watch at the tomb where [Christ’s] venerable body had been placed and from which he had departed by rising. Hence we must strive meticulously my brothers, when we come into the church to pay the due service of divine praise or to perform the solemnity of the mass, to be always mindful of the angelic presence and to fulfill our heavenly duty with fear and fitting veneration, following the example of the women devoted to God who were afraid when the angels appeared to them at the tomb, and who, we are told, bowed their faces to the earth.

[AD 430] Augustine of Hippo on Psalms 138:2
"I will worship toward Your holy Temple" [Psalm 138:2]. What holy Temple? That where we shall dwell, where we shall worship. For we hasten that we may adore. Our heart is pregnant and comes to the birth, and seeks where it may bring forth. What is the place where God is to be worshipped?..."The Temple of God is holy," says the Apostle, "which Temple you are." [1 Corinthians 3:17] But assuredly, as is manifest, God dwells in the Angels. Therefore when our joy, being in spiritual things, not in earthly, takes up a song to God, to sing before the Angels, that very assembly of Angels is the Temple of God, we worship toward God's Temple. There is a Church below, there is a Church above also; the Church below, in all the faithful; the Church above, in all the Angels. But the God of Angels came down to the Church below, and Angels ministered to Him on earth, [Matthew 4:11] while He ministered to us; for, "I came not," says He, "to be ministered unto, but to minister." [Matthew 20:28] ...The Lord of Angels died for man. Therefore, "I will worship toward Your holy Temple;" I mean, not the temple made with hands, but that which You have made for Yourself.

[AD 430] Augustine of Hippo on Psalms 138:3
"In what day soever I call upon You, do Thou quickly hear me" [Psalm 138:3]. Wherefore, "quickly"? Because You have said, "While yet you are speaking I will say, Lo, here I am." [Isaiah 58:9] Wherefore, "quickly"? Because now I seek not earthly happiness, I have learned holy longings from the New Testament. I seek not earth, nor earthly abundance, nor temporal health, nor the overthrow of my enemies, nor riches, nor rank: nought of these do I seek: therefore "quickly hear me." Since You have taught me what to seek, grant what I seek....

[AD 430] Augustine of Hippo on Psalms 138:4
"Let all the kings of the earth confess to You, O Lord" [Psalm 138:4]. So shall it be, and so it is, and that daily; and it is shown that it was not said in vain, save that it was future. But neither let them, when they confess to You, when they praise You, desire earthly things of You. For what shall the kings of the earth desire? Have they not already sovereignty? Whatever more a man desire on earth, sovereignty is the highest point of his desire. What more can he desire? It must needs be some loftier eminence. But perhaps the loftier it is, the more dangerous. And therefore the more exalted kings are in earthly eminence, the more ought they to humble themselves before God. What do they do? "Because they have heard all the words of Your mouth." In a certain nation were hidden the Law and the Prophets, "all the words of Your mouth:" in the Jewish nation alone were "all the words of Your mouth," the nation which the Apostle praises, saying, "What advantage has the Jew? Much every way; chiefly because that unto them were committed the oracles of God." These were the words of God. [Romans 3:1-2] ...What meant Gideon's fleece? It is like the nation of the Jews in the midst of the world, which had the grace of sacraments, not indeed openly manifested, but hidden in a cloud, or in a veil, like the dew in the fleece. [Judges 6:37, 39] The time came when the dew was to be manifested in the floor; it was manifested, no longer hidden. Christ alone is the sweetness of dew: Him alone you recognise not in Scripture, for whom Scripture was written. But yet, "they have heard all the words of your mouth."

[AD 430] Augustine of Hippo on Psalms 138:5
"And let them sing in the paths of the Lord, that great is the glory of the Lord" [Psalm 138:5]. Let all the kings of the earth sing in the paths of the Lord. In what paths? Those that are spoken of above, "in Your mercy and Your truth." Let not then the kings of the earth be proud, let them be humble. Then let them sing in the ways of the Lord, if they be humble: let them love, and they shall sing. We know travellers that sing; they sing, and hasten to reach the end of their journey. There are evil songs, such as belong to the old man; to the new man belongs a new song. Let then the kings of the earth too walk in Your paths, let them walk and sing in Your paths. Sing what? That "great is the glory of the Lord," not of kings.

[AD 430] Augustine of Hippo on Psalms 138:6
See how he willed that kings should sing on their way, humbly bearing the Lord, not lifting themselves up against the Lord. For if they lift themselves up, what follows? "For the Lord is high, and has respect unto the lowly" [Psalm 138:6]. Do kings then desire that He have respect unto them? Let them be humble. What then? If they lift themselves up to pride, can they escape His eyes? Lest perchance, because you have heard, "He has respect unto the lowly," thou choose to be proud, and say in your soul, God has respect unto the lowly, He has not respect unto me, I will do what I will. O foolish one! Would you say this, if you knew what you ought to love? Behold, even if God wills not to see you, do you not fear this very thing, that He wills not to see you?...The lofty then, it seems, He has not respect unto, for it is the lowly He respects. "The lofty"— what? "He considers from afar." What then gains the proud? To be seen from afar, not to escape being seen. And think not that you must needs be safe on that account, for that He sees less clearly, who sees you from afar. For thou indeed see not clearly, what you see from afar; God, although He see you from afar, sees you perfectly, yet is He not with you. This you gain, not that you are less perfectly seen, but that you are not with Him by whom you are seen. But what does the lowly gain? "The Lord is near unto them that are of a contrite heart." Let the proud then lift himself up as much as he will, certainly God dwells on high, God is in heaven: do you wish that He come near to you? Humble yourself. For the higher will He be above you, the more you lift yourself up.

[AD 430] Augustine of Hippo on Psalms 138:6
Perhaps because [the psalm] said, “The Lord is sublime and observes lowly things,” you say to yourself, “Then he does not observe me.” What could be more unfortunate than you, if he does not observe you but ignores you? Observing indicates compassion; ignoring indicates contempt. But no doubt, because the Lord observes lowly things, you imagine you escape his notice, because you are not humble or lowly, you are high and mighty, you are proud. That is not the way to be missed by the eyes of God. I mean, just see what it says there: “The Lord is sublime.” Sublime indeed. How are you going to get to him? Will you look for a ladder? Look for the wood of humility, and you have already gotten to him. “The Lord is sublime, he observes lowly things, but high and mighty things” (do not imagine you escape notice, you that are so proud) “but high and mighty things he knows from afar.” He knows them, all right, but from afar. “Salvation is far from sinners.”

[AD 430] Augustine of Hippo on Psalms 138:6
We have heard, and it is clear; we had gone outside, we have been sent within. “O would that I had found,” you said, “some high and lonely mountain! For, I believe, because God is on high, he hears me from a high place.” Because you are on a mountain, do you think that you are near God and that you are heard quickly, as if shouting from nearby? He dwells on high, but “he looks on the lowly.” “The Lord is near.” To whom? Perhaps to the high? “To those who are contrite of heart.” It is a wondrous thing: he both lives on high and draws near to the lowly. “He looks on the lowly, but the high he knows from afar.” He sees the proud from afar; the higher they seem to themselves, so much of the less does he approach them.

[AD 542] Caesarius of Arles on Psalms 138:6
Today we are keeping the solemn festival of the ascension. If, therefore, we celebrate the Lord’s ascension in a manner that is right, holy, faithful, devout and pious, we must ascend with him and lift up our hearts. Now as we ascend, let us not be lifted up with pride or presume on our merits as if they were our own. For we ought indeed to lift up our hearts, but to the Lord alone. A heart lifted up but not to the Lord is called pride; a heart lifted up to the Lord is called a refuge. See, brethren, the great miracle. God is on high. You exalt yourself, and he flees from you; you humble yourself, and he descends to you. Why is this? Because “the Lord is exalted, yet the lowly he sees, and the proud he knows from afar.” He recognizes what is lowly from close at hand in order that he may raise it up; what is high, that is, what is proud, he knows from afar in order that he may bring it down. Christ truly arose from the dead in order to give us hope, because the person who dies rises again. He gave us assurance, so that we might not despair in dying and think our whole life ended in death. We were troubled about our very soul, but by rising from the dead he also gave us confidence in the resurrection of the body.

[AD 430] Augustine of Hippo on Psalms 138:7
"If I walk in the midst of tribulation, You shall revive me" [Psalm 138:7]. True it is: whatsoever tribulation you are in, confess, call on Him; He frees you, He revives you....Love the other life, and you shall see that this life is tribulation, whatever prosperity it shine with, whatever delights it abound and overflow with; since not yet have we that joy most safe and free from all temptation, which God reserves for us in the end, without doubt it is tribulation. Let us understand then what tribulation he means here too, brethren. Not as though he said, "If perchance there shall any tribulation have befallen me, You shall free me therefrom." But how says he? "If I walk," etc.; that is, otherwise You will not revive me, unless I walk in the midst of tribulation.

[AD 430] Augustine of Hippo on Psalms 138:8
"You, Lord, shall recompense for me" [Psalm 138:8]. I recompense not: You shall recompense. Let mine enemies rage their full: You shall recompense what I cannot...."Dearly beloved, avenge not yourselves," says the Apostle, "but rather give place unto wrath; for it is written, Vengeance is Mine, I will repay, says the Lord." [Romans 12:19] There is here another sense not to be neglected, perhaps even to be preferred. "Lord" Christ, "You shall repay for me." For I, if I repay, have seized; You have paid what You have not seized. Lord, You shall "repay for me." Behold Him repaying for us. They came to Him, who exacted tribute: [Matthew 17:24-26] they used to demand as tribute a didrachma, that is, two drachmas for one man; they came to the Lord to pay tribute; or rather, not to Him, but to His disciples, and they said to them, "Does not your Master pay tribute?" They came and told Him. He says unto Peter, "lest we should offend them, go thou to the sea, and cast an hook, and take up the fish that first comes up: and when you have opened his mouth, you shall find a stater: that take, and give for Me and you." The first that rises from the sea, is the First-begotten from the dead. In His mouth we find two didrachmas, that is, four drachmas: in His mouth we find the four Gospels. By those four drachmas we are free from the claims of this world, by the four Evangelists we remain no longer debtors; for there the debt of all our sins is paid. He then has repaid for us, thanks to His mercy. He owed nothing: He repaid not for Himself: He repaid for us....