To perform mercy to our fathers, and to remember his holy testament,

“I think that at the coming of our Lord and Saviour Jesus Christ, both Abraham, Isaac, and Jacob, were partakers of His mercy. For it is not to be believed, that they who had before seen His day, and were glad, should afterwards derive no advantage from His coming, since it is written, Having made peace through the blood of his Cross, whether in earth or in heaven. (Coloss. 1:20.)”

“(Hom. in Ps. 29. et in Ps. 14. App. op.) But let no one, hearing that the Lord had sworn to Abraham, be tempted to swear. For as when the wrath of God is spoken of, it does not signify passion but punishment; so neither dos God swear as man, but His word is in very truth expressed to us in place of an oath, confirming by an unchangeable sentence what He promised.”

“Having announced that the Lord, according to the declaration of the Prophet, would be born of the house of David, he now says, that the same Lord to fulfil the covenant He made with Abraham will deliver us, because chiefly to these patriarchs of Abraham’s seed was promised the gathering of the Gentiles, or the incarnation of Christ. But David is put first, because to Abraham was promised the holy assembly of the Church; whereas to David it was told that from him Christ was to be born. And therefore after what was said of David, he adds concerning Abraham the words, To perform the mercy promised to our fathers, &c.”

“The grace of Christ extends even to those who are dead, because through Him we shall rise again, not only we, but they also who have been dead before us. He performed His mercy also to our forefathers in fulfilling all their hopes and desires. Hence it follows, And to remember his holy covenant, that covenant, namely, wherein he said, Blessing, I will bless thee, and multiplying, I will multiply thee. (Gen. 22:17.) For Abraham was multiplied in all nations, who became his children by adoption, through following the example of his faith. But the fathers also, seeing their children enjoy these blessings, rejoice together with them, just as if they received the mercy in themselves. Hence it follows, The oath which he sware to our father Abraham, that he would grant unto us.”

“To perform the mercy promised to our fathers,.... By "mercy" is meant salvation by Christ, which springs from the mercy of God; the promise of which was an instance of mercy to the Jewish fathers under the Old Testament, and also the performance of it; for they were saved by the grace of our Lord Jesus, even as we: his blood was shed for the remission of sins that were past, and for the redemption of transgressions under the first Testament: and to remember his holy covenant; which was made between him, and his Son from all eternity; and was, at various times, dispensed and manifested to the patriarchs, and eminent saints, as Adam, Noah, Abraham, &c. This is called an "holy" one; not only because it was made by, and between holy persons, and provided for the holiness of the people of God, both here, and hereafter; but because in the article of redemption and salvation by Christ, which is here more particularly regarded, care was taken to secure the glory of God's holiness and justice, as well as to display his grace and mercy. Now raising up, and sending Jesus a Saviour, showed, that God was mindful of this covenant, and therefore sent redemption to his people.”

“To remember his holy covenant, i.e. of his promise, or of the covenant made with Abraham, that he would bless all nations in his seed. (Witham) — At the coming of Christ, Abraham, Isaac and Jacob were made partakers of his mercy. For, we cannot suppose that they who saw his day, and were glad, should not participate in the fruit of his coming; since St. Paul says: he maketh peace through the blood of the cross, both to the things that are on earth, and the things that are in heaven. (Colossians i. 20.) (Origen, hom. x.)”