Catena Aurea on Luke 3:23–38: Augustine of Hippo

It is most probable that Luke took the origin by adoption, as not being willing to say that Joseph, was begotten by him whose son he related him to be. For more easily is a man said to be his son by whom he was adopted, than to be begotten by him from whose flesh he was not born. But Matthew saying, “Abraham begat lsaac, and Isaac begat Jacob,” and continuing in the word “begat,” until at last he says, but “Jacob begat Joseph,” has sufficiently expressed that he has carried through the succession of the fathers, to that father by whom Joseph was not adopted, but begotten. Although even supposing that Luke should say that Joseph was begotten by Eli, neither ought that word to perplex us. For it is not absurd to say that a man has begotten not in the flesh but in love the Son whom he has adopted. But rightly has Luke taken the origin by adoption, for by adoption are we made the sons of God, by believing on the Son of God, but by His birth in the flesh, the Son of God has rather for our sakes become the Son of man.