But let us proceed with our inquiry into some eminent chief fathers of our origin: for there are some to whom our monogamist parents Adam and Noah are not pleasing, nor perhaps Christ either. To Abraham, in fine, they appeal; prohibited though they are to acknowledge any other father than God. Grant, now, that Abraham is our father; grant, too, that Paul is. “In the Gospel,” says he, “I have begotten you.” Show yourself a son even of Abraham. For your origin in him, you must know, is not referable to every period of his life: there is a definite time at which he is your father. For if “faith” is the source whence we are reckoned to Abraham as his “sons” (as the apostle teaches, saying to the Galatians, “You know, consequently, that (they) who are of faith, these are sons of Abraham”), when did Abraham “believe God and it was accounted to him for righteousness?” I suppose when still in monogamy, since (he was) not yet in circumcision. But if afterwards he changed to either (opposite)—to digamy through cohabitation with his handmaid, and to circumcision through the seal of the testament—you cannot acknowledge him as your father except at that time when he “believed God,” if it is true that it is according to faith that you are his son, not according to flesh. Else, if it be the later Abraham whom you follow as your father—that is, the digamist (Abraham)—receive him withal in his circumcision. If you reject his circumcision, it follows that you will refuse his digamy too. Two characters of his mutually diverse in two several ways, you will not be able to blend. His digamy began with circumcision, his monogamy with uncircumcision. You receive digamy; admit circumcision too. You retain uncircumcision; you are bound to monogamy too. Moreover, so true is it that it is of the monogamist Abraham that you are the son, just as of the uncircumcised, that if you be circumcised you immediately cease to be his son, inasmuch as you will not be “of faith,” but of the seal of a faith which had been justified in uncircumcision. You have the apostle: learn (of him), together with the Galatians. In like manner, too, if you have involved yourself in digamy, you are not the son of that Abraham whose “faith” preceded in monogamy. For albeit it is subsequently that he is called “a father of many nations,” still it is of those (nations) who, as the fruit of the “faith” which precedes digamy, had to be accounted “sons of Abraham.”