Augustine of Hippo : The greatest cause for triumph in Abraham was that, before his circumcision, faith was reckoned to him for righteousness. This is most correctly referred to the promise that "All nations shall be blessed in you," meaning of course by the following of his faith, by which he was justified even before the ordinance of circumcision, which he received as a token of faith, and long before the servitude of the law, which was given much later. — EPISTLE TO THE Galatians 20 [1B.3.2-9] Jerome : (Verse 8, 9.) But the Scripture, foreseeing that by faith God would justify the Gentiles, foretold to Abraham that all nations would be blessed in him. So then, those who are of faith are blessed with faithful Abraham. Not that the Scripture itself, namely the ink and the parchment, which are insensible, can foreknow the future; but rather the Holy Spirit and the senses, hidden in the letter, have foretold things to come many centuries later. Moreover, the example taken from Genesis is contained in its own volume: 'And in your seed all the nations of the earth shall be blessed' (Gen. XXVI, 4). The apostle interpreted this concerning Christ, saying: 'It is not written of seeds, as if in many; but as in one, and in your seed, which is Christ.' However, we must observe in all the almost testimonies (as taken from the old books in the new Testament), which the evangelists or apostles believed in memory; and having only explained the meaning, they often changed the order, and sometimes removed or added words. But there is no doubt that all nations were blessed in Isaac and Jacob, or in the twelve patriarchs, and others who descended from the lineage of Abraham; but in Christ Jesus, through whom all nations praise God, and a new name is blessed on the earth. However, the apostle can also be understood to have drawn an example of the seed from another passage in Genesis, where it is written: 'And (no doubt Abraham) God brought him outside and said to him: Look up at the sky and count the stars, if you are able to count them.' And he said to him: Thus shall your seed be; and Abraham believed God, and it was reputed to him unto justice (Gen. XV, 5, 6) . Therefore, whoever believes, shall be blessed with faithful Abraham, who is said to have believed in God first, for his remarkable faith in him. Just as Enos is said to have hoped in the Lord God, the principal hope in God, and above all the others, is written to have called upon the Lord God (Gen. IV, 26) . Not that Abel, about whom the Lord says: The voice of your brother's blood cries to me (Ibid. IV, 10) ; and the others afterwards, did not hope to call upon God; but each one may be called upon from the part that he has, to the greatest extent possible. — Commentary on Galatians Jerome : God, providing that the descendants of Abraham should not be mixed with the other nations … marked off the Israelite people by a particular rite: circumcision.… After that for forty years no one was circumcised in the wilderness. They were living without any intermixing with other nations.… As soon as the people crossed the river Jordan and the host poured out onto the territory of Judea in Palestine, he made provision by a necessary circumcision against the future error from miscegenation with the Gentiles. But the fact that the people are said to have been circumcised a second time by their leader Joshua signifies that circumcision had ceased in the wilderness, though practiced in Egypt for a good reason. Believers now are cleansed by our Lord Jesus Christ through a spiritual circumcision. — EPISTLE TO THE Galatians 3.7 John Chrysostom : If then those were Abraham's sons, not, who were related to him by blood, but who follow his faith, for this is the meaning of the words, "In thee all the nations," it is plain that the heathen are brought into kindred with him. Hereby too is proved another important point. It perplexed them that the Law was the older, and Faith afterwards. Now he removes this notion by showing that Faith was anterior to the Law; as is evident from Abraham's case, who was justified before the giving of the Law. He shows too that late events fell out according to prophecy; "The Scripture," says he, "foreseeing that God would justify the Gentiles by faith, preached the Gospel beforehand unto Abraham." Attend to this point. He Himself who gave the Law, had decreed, before He gave it, that the heathen should be justified by Faith. And he says not "revealed," but, "preached the Gospel," to signify that the patriarch was in joy at this method of justification, and in great desire for its accomplishment. — Homily on Galatians 3 Oecumenius : "preached the gospel beforehand." As signifying a great good, salvation through faith. For this is what the phrase "preached the gospel beforehand" indicates. "In you shall all the nations be blessed." The "in you" that is, in your seed, who is Christ. But how are they blessed? Through faith, namely, of which Abraham is the pioneer. Moreover, the "in you" can be understood as through the faith from him. The "in you," according to your pattern and likeness, is interpreted by Saint Cyril, in the second book of his treatise on worship, which is On the Spirit and on Truth, interprets at the beginning of the book ἐν σοί as "in you," that is, to your imitation and likeness. — Commentary on Galatians Tertullian : And if of Abraham, how much more, to be sure, of David, as a more recent progenitor! For, unfolding the promised blessing upon all nations in the person of Abraham, "And in thy seed shall all nations of the earth be blessed," he adds, "He saith not, And to seeds, as of many; but as of one, And to thy seed, which is Christ." When we read and believe these things, what sort of flesh ought we, and can we, acknowledge in Christ? Surely none other than Abraham's, since Christ is "the seed of Abraham; "none other than Jesse's, since Christ is the blossom of "the stem of Jesse; "none other than David's, since Christ is "the fruit of David's loins; "none other than Mary's, since Christ came from Mary's womb; and, higher still, none other than Adam's, since Christ is "the second Adam. — On the Flesh of Christ