John Chrysostom

See you how he shows the Jews to be as it were of the class of parasites (i.e. guests), rather than those in uncircumcision, and that these were added to the others? For if he was justified and crowned while in uncircumcision, the Jews came in afterwards, Abraham is then the father first of the uncircumcised, which through faith appertain to him, and then of those in the circumcision. For he is a forefather of two lines. See you faith lightening up? for till it came the patriarch was not justified. See you the uncircumcision offering no hindrance? for he was uncircumcised, yet was not hindered from being justified. The circumcision therefore is behind the faith. And why wonder that it is behind the faith, when it is even behind the uncircumcision. Nor is it behind faith only, but very far inferior to it, even so far as the sign is to the reality of which it is the sign; for instance, as the seal is to the soldier. And why, he says, did he want a seal then? He did not want it himself. For what purpose then did he receive it? With a view to his being the father alike of them that believe in uncircumcision and in circumcision. But not of those in circumcision absolutely: wherefore he goes on to say, "To them who are not of the circumcision only." For if to the uncircumcised, it is not in that he is uncircumcised that he is their father, although justified in uncircumcision; but in that they imitated his faith; much less is it owing to circumcision that he is the forefather of those in the state of circumcision, unless faith also be added.