Romans 4:1

“What shall we say then, etc..] The apostle having proved that there is no justification by the works of the law; to make this appear more clear and evident to the Jews, he instances in the greatest person of their nation, and for whom they had the greatest value and esteem, Abraham, our father; who was not a righteous and good man, but the head of the Jewish nation; and, as the Syriac version here styles him, athbad açyr, “the head”, or “chief of the fathers”; and so the Alexandrian copy, “our forefather”: and was the first of the circumcision, and is described here by his relation to the Jews, “our father”; that is, as pertaining to the flesh; or according to carnal descent, or natural…”

“THE FOREGOING DOCTRINE OF JUSTIFICATION BY FAITH ILLUSTRATED FROM THE OLD TESTAMENT. (Rom. 4:1-25) What shall we say then that Abraham, our father as pertaining to the flesh, hath found?--that is, (as the order in the original shows), "hath found, as pertaining to ('according to,' or 'through') the flesh"; meaning, "by all his natural efforts or legal obedience."”

“What shall we say then? - See Romans 3:1. This is rather the objection of a Jew. “How does your doctrine of justification by faith agree with what the Scriptures say of Abraham? Was the Law set aside in his case? Did he derive no advantage in justification from the rite of circumcision, and from the covenant which God made with him?” The object of the apostle now is to answer this inquiry. That Abraham our father - Our ancestor; the father and founder of the nation; see the note at Matthew 3:9 The Jews valued themselves much on the fact that he was their father; and an argument, drawn from his example or conduct, therefore, would be especially forcible. As pertaining to the flesh - This…”

“That our father Abraham hath found - Acceptance with God. According to the flesh - That is, by works. Romans 4:2”

“4:1 Jews in Paul’s day revered Abraham as Israel’s founder. Some Jewish texts claim that Abraham never sinned (Prayer of Manasseh 8; Jubilees 23:10). Others emphasize his obedience to the law of Moses as the basis for his relationship with God (1 Maccabees 2:52; Sirach 44:19-20). However, Paul demonstrates that Abraham’s faith, not his obedience, established his status with God. Abraham’s position as the founder of God’s people demonstrates that justification by faith is central in God’s plan.”

“what: Rom 6:1, Rom 7:7, Rom 8:31 Abraham: Isa 51:2; Mat 3:9; Luk 3:8, Luk 16:24, Luk 16:25, Luk 16:29-31; Joh 8:33, Joh 8:37-41, Joh 8:53, Joh 8:56; Act 13:26; Co2 11:22 as pertaining: Rom 4:16; Heb 12:9 Romans 4:2”