City of God

Now, as Isaac's two sons, Esau and Jacob, furnished a type of the two people, the Jews and the Christians (although as pertains to carnal descent it was not the Jews but the Idumeans who came of the seed of Esau, nor the Christian nations but rather the Jews who came of Jacob's; for the type holds only as regards the saying, “The elder shall serve the younger”), so the same thing happened in Joseph's two sons; for the elder was a type of the Jews, and the younger of the Christians.

For when Jacob was blessing them, and laid his right hand on the younger, who was at his left, and his left hand on the elder, who was at his right, this seemed wrong to their father, and he admonished his father by trying to correct his mistake and show him which was the elder. But he would not change his hands, but said, “I know, my son, I know. He also shall become a people, and he also shall be exalted; but his younger brother shall be greater than he, and his seed shall become a multitude of nations.” And these two promises show the same thing.

For that one is to become “a people;” this one “a multitude of nations.” And what can be more evident than that these two promises comprehend the people of Israel, and the whole world of Abraham's seed, the one according to the flesh, the other according to faith?