John Calvin Commentary Isaiah 61:9

"And their seed shall be known among the nations, and their offspring among the peoples; all that see them shall acknowledge them, that they are the seed which Jehovah hath blessed." — Isaiah 61:9 (ASV)

And their seed shall be known among the Gentiles. Here the Prophet deals more clearly with the extension of the Church, which at that time could be said to be confined within a narrow corner of the earth, and afterwards, as we have already seen, was greatly diminished and impaired (Isaiah 1:9; Isaiah 10:22). Isaiah therefore discusses the Church, which, after having suffered such a great reduction, would be spread throughout the whole world, so that it would be visible to all the nations. And yet this did not happen even in the reign of Solomon, when the Jews flourished most in wealth and splendor (1 Kings 10:21, 27). Now this seemed entirely incredible; and that is why the prophets take such pains to convince people of it, and repeat it very often, so that the Jews would not measure this restoration by their own understanding or by the present appearance of things.

A question now arises: When did these things happen? I reply (as I have often done before) that they began when the people returned to their native country; for at that time, and in uninterrupted succession, they experienced the manifold kindness of God toward them. But as nothing more than feeble sparks appeared, the full brightness shone forth in Christ, in whose reign those things are entirely accomplished. For where there was the greatest barrenness of godliness, the offspring of Abraham sprouted, because foreigners were grafted by faith into the elect people. Thus foreign and barbarous nations acknowledged that the Jews were the blessed seed of God (Genesis 22:18), when they united with them in the same confession of faith. Nor was this fulfilled only once, but it is in the course of being fulfilled every day.

Regarding the Jews going before, and holding the first rank in God’s covenant, this should be ascribed to the mercy of God, and not to their own excellence, as Paul (Romans 3:2) teaches. For, after having shown that by nature they do not differ at all from the Gentiles, and after having subjected them to the same condemnation, he likewise teaches that they hold this privilege of preeminence because they were the very first to receive the word of God and the promises. But this proceeded from God’s undeserved kindness, and not from their merits or excellence.