Augustine of Hippo — as excerpted in the Catena Aurea on John 1:11-13

“(Tr. ii. 14) To be made then the sons of God, and brothers of Christ, they must of course be born; for if they are not born, how can they be sons? Now the sons of men are born of flesh and blood, and the will of man, and the embrace of wedlock; but how these are born, the next words declare: Not of bloods1; that is, the male’s and the female’s. Bloods is not correct Latin, but as it is plural in the Greek, the translator preferred to put it so, though it be not strictly grammatical, at the same time explaining the word in order not to offend the weakness of one’s hearers.”