And he received the sign of circumcision as a seal of the righteousness that he had by faith while he was still uncircumcised. So then, he is the father of all who believe but are not circumcised, in order that righteousness might be credited to them.
11. And he received the sign, etc. In order to anticipate an objection, he shows that circumcision was not unprofitable and superfluous, though it could not justify; but it had another very remarkable use, it had the office of sealing, and as it were of ratifying the righteousness of faith.
St. Paul observes in this paragraph when and why Abraham was thus justified; for he has several things to remark upon that. It was before he was circumcised, and before the giving of the law; and there was a reason for both. I. It was before he was circumcised, Rom 4:10. His faith was counted to him for righteousness while he was in uncircumcision.
Commenting on Romans 4:9-16
And the father of circumcision,.... So the Jews call Abraham (l), "the head of those that are circumcised"; and (m), "the head to them that are circumcised"; but the apostle here says, he is a father to them who are not of the circumcision only; not to the Jews only, in a spiritual sense, and not to all of them, since some were "of Israel"...