Romans 4: 9: Cometh this blessedness then upon the circumcision only, or upon the uncircumcision also? for we say that faith was reckoned to Abraham for righteousness. 10: How was it then reckoned? when he was in circumcision, or in uncircumcision? Not in circumcision, but in uncircumcision.
This blessedness is the blessedness which David describes in verses 6-8. It is God imputing righteousness to a sinner without the sinner's obedience to the law. Our iniquities are forgiven; our sins are covered. The Lord will not charge the believer with sin ever again. This blessedness begins and ends with God and is toward ruined and helpless sinners. Therefore this blessedness is completely by the free grace of God alone. The Holy Spirit moves Paul to ask these questions to prove that very fact.
Therefore Paul writes, "Cometh this blessedness then upon the circumcision only, or upon the uncircumcision also?" Does this blessing from God come upon those who are under the law in Israel or also upon those who never have been under the law in Israel? Abraham is held up as the father of the faithful so the question is asked, "We say that through faith Christ's righteousness was imputed to Abraham. How was it then reckoned? When he was in circumcision, or in uncircumcision?" The answer is plain. Not in circumcision, but in uncircumcision.
Circumcision stands for the whole law. Paul expressed that very thing to the Galatians when he said that if they were circumcised, Christ and his work would do them no good because they were debtors to do the whole law? So then the law had nothing to do with Abraham receiving this blessedness from the Lord. Fact is Abraham was never even under the covenant of works which national Israel was under. Proof is circumcision came 15 years after Abraham received this blessedness and the law of Sinai came 430 years after.
Abraham was not under the law when the Lord came to him in Ur of Chaldee's. Abraham was not under Israel's law when God called him out of his imaginary religion. He did not possess the Ten Commandments when the Lord freely bestowed this blessing upon him nor all the days of his life and yet he was called, "The friend of God."
The Holy Spirit is teaching us that this blessedness came upon Abraham, the same way it comes upon all of Christ's redeemed. Righteousness is free. It is by the grace of God. This blessedness is received by the believer through God-given faith. The law has no bearing on this blessedness, whatsoever. Read verse 13, "For the promise, that he should be the heir of the world, was not to Abraham, or to his seed, through the law, but through the righteousness of faith."
To sum up, the Lord saved Abraham prior to giving the law to teach his elect in every age that this blessedness is by his free grace, by the faith of Christ alone, through faith in him alone, without any regard whatsoever to the law of the Mosaic covenant. So Paul concludes, therefore it is of faith, that it might be by grace; to the end the promise might be sure to all the seed; not to that only which is of the law, but to that also which is of the faith of Abraham; who is the father of us all (Rom 4: 16.)
Heed Paul's gospel, "Christ is become of no effect unto you, whosoever of you are justified by the law; ye are fallen from grace" (Gal 5:4.)