For the one and the same Spirit of God, who proclaimed by the prophets what and of what sort the advent of the Lord should be, did by these elders give a just interpretation of what had been truly prophesied; and He did Himself, by the apostles, announce that the fulness of the times of the adoption had arrived, that the kingdom of heaven had drawn nigh, and that He was dwelling within those that believe on Him who was born Emmanuel of the Virgin. To this effect they testify, [saying,] that before Joseph had come together with Mary, while she therefore remained in virginity, "she was found with child of the Holy Ghost;" [Matthew 1:18] and that the angel Gabriel said unto her, "The Holy Ghost shall come upon thee, and the power of the Highest shall overshadow thee; therefore also that holy thing which shall be born of thee shall be called the Son of God;" [Luke 1:35] and that the angel said to Joseph in a dream, "Now this was done, that it might be fulfilled which was spoken by Isaiah the prophet, Behold, a virgin shall be with child." [Matthew 1:23] But the elders have thus interpreted what Esaias said: "And the Lord, moreover, said unto Ahaz, Ask for thyself a sign from the Lord thy God out of the depth below, or from the height above. And Ahaz said, I will not ask, and I will not tempt the Lord. And he said, It is not a small thing for you to weary men; and how does the Lord weary them? Therefore the Lord himself shall give you a sign; Behold, a virgin shall conceive, and bear a son; and ye shall call His name Emmanuel. Butter and honey shall He eat: before He knows or chooses out things that are evil, He shall exchange them for what is good; for before the child knows good or evil, He shall not consent to evil, that He may choose that which is good." [Isaiah 7:10-17] Carefully, then, has the Holy Ghost pointed out, by what has been said, His birth from a virgin, and His essence, that He is God (for the name Emmanuel indicates this). And He shows that He is a man, when He says, "Butter and honey shall He eat;" and in that He terms Him a child also, [in saying,] "before He knows good and evil;" for these are all the tokens of a human infant. But that He "will not consent to evil, that He may choose that which is good,"— this is proper to God; that by the fact, that He shall eat butter and honey, we should not understand that He is a mere man only, nor, on the other hand, from the name Emmanuel, should suspect Him to be God without flesh.
Isaiah 7:15
15 Butter and honey shall he eat, that he may know to refuse the evil, and choose the good.
Commentaries
(Verse 15) He shall eat butter and honey, so that he may know how to refuse the evil and choose the good. For before he knows to refuse the evil and choose the good, the land that you dread will be forsaken by both her kings. The Lord will bring the king of Assyria upon you and your people and your father's house—days that have not come since the day that Ephraim departed from Judah. And it shall come to pass in that day, that the Lord shall hiss for the fly that is in the uttermost part of the rivers of Egypt, and for the bee that is in the land of Assyria. And they shall come, and shall rest all of them in the desolate valleys, and in the holes of the rocks, and upon all thorns, and upon all bushes. I will say something even more amazing, so that you do not think that he is born in a fantasy, he will use foods of infancy, he will eat butter and milk. And although many centuries later the Evangelist testifies about him: But the child grew in wisdom and age and grace before God and men (Luke 2:52): and this is said to confirm the truth of the human body: yet still wrapped in swaddling clothes, and fed with butter and honey, he will have the ability to judge between good and evil, so that he may reject evil and choose good. Not because he did or disapproved or chose this, but because he knew how to disapprove and choose, so that through these words we may know that the infancy of the human body did not hinder divine wisdom. Lastly, the Angels announce to the shepherds the laying in the manger: The Magi adore coming from the East, whom it is to be believed were certainly chosen. And on the other hand, Herod, the scribes, and the Pharisees are disapproved, (Matthew 2), because they killed many thousands of infants for the sake of one child.
Source: Commentary on Isaiah
I will say something even more amazing, so that you do not think that he is born in a fantasy, he will use foods of infancy, he will eat butter and milk. And although many centuries later the Evangelist testifies about him: But the child grew in wisdom and age and grace before God and men (Luke 2:52): and this is said to confirm the truth of the human body: yet still wrapped in swaddling clothes, and fed with butter and honey, he will have the ability to judge between good and evil, so that he may reject evil and choose good. Not because he did or disapproved or chose this, but because he knew how to disapprove and choose, so that through these words we may know that the infancy of the human body did not hinder divine wisdom. Lastly, the Angels announce to the shepherds the laying in the manger: The Magi adore coming from the East, whom it is to be believed were certainly chosen. And on the other hand, Herod, the scribes, and the Pharisees are disapproved, (Matthew 2), because they killed many thousands of infants for the sake of one child.
(Verse 16) For before the boy knows how to reject evil and choose good, the land that you detest will be abandoned by the face of its two kings. In the sixth year of the reign of Hezekiah, Samaria was captured by the Assyrians (2 Kings 18), that is, in his thirty-first year of age. Therefore, this one who is to be born, either from a Virgin, as we believe, or from a young woman, as the Jews claim, will eat butter and honey, and will be so young that he cannot discern between evil and good, and before he leaves infancy, the land of Syria and Samaria will be laid waste by the Assyrians. Let the Hebrews answer how Hezekiah is proclaimed an infant at the age of thirty-one, and of such a young age that he, eating honey and butter, like the children of Nineveh, does not know left from right, that is, does not know evil from good. But in regard to Emmanuel, which means 'God is with us,' he will have an easy understanding. As for the mystery and invocation of his name, let the land of Syria and Samaria be laid waste, even by the Assyrians who prevail, and let the house of David be freed from the two kings whom he fears, namely, Rezin and Pekah.
(Verse 16) For before the boy knows how to reject evil and choose good, the land that you detest will be abandoned by the face of its two kings. In the sixth year of the reign of Hezekiah, Samaria was captured by the Assyrians (2 Kings 18), that is, in his thirty-first year of age. Therefore, this one who is to be born, either from a Virgin, as we believe, or from a young woman, as the Jews claim, will eat butter and honey, and will be so young that he cannot discern between evil and good, and before he leaves infancy, the land of Syria and Samaria will be laid waste by the Assyrians. Let the Hebrews answer how Hezekiah is proclaimed an infant at the age of thirty-one, and of such a young age that he, eating honey and butter, like the children of Nineveh, does not know left from right, that is, does not know evil from good. But in regard to Emmanuel, which means 'God is with us,' he will have an easy understanding. As for the mystery and invocation of his name, let the land of Syria and Samaria be laid waste, even by the Assyrians who prevail, and let the house of David be freed from the two kings whom he fears, namely, Rezin and Pekah.
Source: Commentary on Isaiah
Now, since the Lord was not a mere man but was also God and knew all things, he stood in no need of reflection, inquiry, counsel or judgment. He also had a natural affinity for good and antipathy for evil. Thus it is in this sense that the prophet Isaiah, too, says, "Before the child shall know to refuse the evil, he will choose the good. For before the child knows to refuse the evil and to choose the good, he will reject the evil by choosing the good." The "before" shows that he made no inquiry or investigation in a human manner but that since he was God and divinely subsisted in the flesh—that is to say, was personally united to the flesh—by the fact of his very being and his knowing all things he naturally possessed the good.
Source: ORTHODOX FAITH 3:14
Second, as to his humanity: he shall eat butter and honey, literally, manly foods, because from infancy he held himself to the manner of other men: and being born, I drew in the common air, and fell upon the earth, that is made alike, and the first voice which I uttered was crying, as all others do (Wis 7:3).
Or from the part to the whole, according to the rules of Tyconius: for through these he understands all human foods. That he may know. The "that" is consecutive, for, feeding on such things, the child still knows to refuse the evil, without experience, and to choose the good, without counsel, having all perfect knowledge. The devil had promised this, but did not fulfill it (Gen 3:5); but God gave it freely: for he has given me the true knowledge of the things that are: to know the disposition of the whole world, and the virtues of the elements (Wis 7:17).
Or, "that" is causal: that he may know, that is, that he may show himself to know, because he is led through the foods to the perfect quantity of years, in which he shows himself to know. Augustine on Song of Songs 4:11, honey and milk, says that humanity is signified by butter, because it comes from the nourishment of the earth; divinity is signified by honey, because it is collected from the dew of heaven. He had, moreover, a nature without corruption, like butter without curd; and he carried consolation without judgment, like honey without the sting. Bernard: our little one chose to be newly conceived, because he took the nature of our flesh without corruption. Similarly, the bee brings us honey without mingling in the sting. He came not to judge the world, but that the world may be saved by him (John 3:17). And thus, "that" is also causal. And this is a sign from below on the part of the virgin giving birth, and from above on the part of God being born: the Lord will give goodness: and our earth shall yield her fruit (Ps 84:13[85:12]).
Or from the part to the whole, according to the rules of Tyconius: for through these he understands all human foods. That he may know. The "that" is consecutive, for, feeding on such things, the child still knows to refuse the evil, without experience, and to choose the good, without counsel, having all perfect knowledge. The devil had promised this, but did not fulfill it (Gen 3:5); but God gave it freely: for he has given me the true knowledge of the things that are: to know the disposition of the whole world, and the virtues of the elements (Wis 7:17).
Or, "that" is causal: that he may know, that is, that he may show himself to know, because he is led through the foods to the perfect quantity of years, in which he shows himself to know. Augustine on Song of Songs 4:11, honey and milk, says that humanity is signified by butter, because it comes from the nourishment of the earth; divinity is signified by honey, because it is collected from the dew of heaven. He had, moreover, a nature without corruption, like butter without curd; and he carried consolation without judgment, like honey without the sting. Bernard: our little one chose to be newly conceived, because he took the nature of our flesh without corruption. Similarly, the bee brings us honey without mingling in the sting. He came not to judge the world, but that the world may be saved by him (John 3:17). And thus, "that" is also causal. And this is a sign from below on the part of the virgin giving birth, and from above on the part of God being born: the Lord will give goodness: and our earth shall yield her fruit (Ps 84:13[85:12]).
Source: Commentary on Isaiah