Isaiah 49:5

(Verse 5, 6 and following) And now says the Lord, who formed me as his servant from the womb, to bring Jacob back to him, and Israel will not be gathered: and I am glorified in the eyes of the Lord, and my God has become my strength. And he said: It is not enough for you to be my servant to raise up the tribes of Jacob and to restore the remnants of Israel. Behold, I have given you (Vulg. Behold I have given you) as a light to the Gentiles, that you may be my salvation to the end of the earth. LXX: And now thus says the Lord who formed me from the womb to be his servant, to gather Jacob to him and Israel: I will gather and be glorified before the Lord, and my God will be my strength. And he said to me: It is a great thing for you to be called my servant, and to raise up the tribes of Jacob, and to convert the dispersion of Israel. Behold, I have set you as a testament to the people, as a light to the Gentiles, that you may be salvation to the end of the earth. While I was speaking, I labored in vain, without cause, and in vain I consumed my strength: because the Jews refused to believe, and my judgment is with the Lord; and my work, which I accomplished with His help, is with the Lord. The Lord answered me, who formed me from the womb to be His servant. From the moment he was formed in the womb, it was shown that he would be called His servant. He also says in the psalm: You are my God from my mother's womb (Psalm 22:10). What then did the Lord say to him? That he should bring Jacob back to him who had strayed, who, having forsaken the Creator, served idols. Hence he himself speaks to his disciples: Do not go on the road of the Gentiles, and do not enter the cities of the Samaritans; but rather go to the lost sheep of the house of Israel (Matthew 10:5); and in another place: I came only for the lost sheep of the house of Israel (Matthew 15:24). […]

For a lowly appellation is given to the Word whose origin is from God, that he is called slave, that is, a household member. For such a title can sometimes indicate "son," and at other times, as we have said, "household member." In the economy of the flesh, it is appropriate to consider the Son as a slave. For he is God by nature and free as being from God the sovereign Father, yet he took the shape or form of a slave. For no one with right understanding could say that he was a slave by nature who was then able to be brought into the form of a slave. Rather, he was outside of slavery and constraint, but for the sake of a sign, in the freedom of his nature, he received the shape, that is, the form of slave.… For he was Emmanuel, and he revealed to us no less in this way his freedom which was real and by nature.… For he who was God the Word dwelled in them and among us for no other reason except so that he could save Israel and gather Jacob. For he had scattered all others who were on the earth, every inventor of wickedness, into their many-colored and multifaceted vices.

"Who formed me from the womb to be his servant." This is clearly said with reference to Zerubbabel and the people but was accomplished in Christ. And indeed, since Christ will descend from them, it is with good reason that what concerns him is represented …

Concerning the first, he does two things. First is set out the claim of the prophet who puts forth his labor in preaching, even though, due to the fault of those who heard it, it bore no fruit, and he concludes: therefore my judgment, for …

But this is directed to the isles (that is, the Gentiles, for they are called the isles of the Gentiles, Gen. x. 5 ) and to the people from far, that were strangers to the commonwealth of Israel, and afar off.