John Calvin on Romans 4:9-10

9-10. As circumcision and uncircumcision are alone mentioned, some unwisely conclude, that the only question is, that righteousness is not attained by the ceremonies of the law. But we ought to consider what sort of men were those with whom Paul was reasoning; for we know that hypocrites, whilst they generally boast of meritorious works, do yet disguise themselves in outward masks. The Jews also had a peculiar way of their own, by which they departed, through a gross abuse of the law, from true and genuine righteousness. Paul had said, that no one is blessed but he whom God reconciles to himself by a gratuitous pardon; it hence follows, that all are accursed, whose works come to judgment. Now then this principle is to be held, that men are justified, not by their own worthiness, but by the mercy of God. But still, this is not enough, except remission of sins precedes all works, and of these the first was circumcision, which initiated the Jewish people into the service of God. He therefore proceeds to demonstrate this also.

We must ever bear in mind, that circumcision is here mentioned as the initial work, so to speak, of the righteousness of the law: for the Jews gloried not in it as the symbol of God’s favor, but as a meritorious observance of the law: and on this account it was that they regarded themselves better than others, as though they possessed a higher excellency before God. We now see that the dispute is not about one rite, but that under one thing is included every work of the law; that is, every work to which reward can be due. Circumcision then was especially mentioned, because it was the basis of the righteousness of the law.

But Paul maintains the contrary, and thus reasons: “If Abraham’s righteousness was the remission of sins, (which he safely takes as granted,) and if Abraham attained this before circumcision, it then follows that remission of sins is not given for preceding merits.” You see that the argument rests on the order of causes and effects; for the cause is always before its effect; and righteousness was possessed by Abraham before he had circumcision.

Romans 4:11-12

11. And he received the sign of circumcision, a seal of the righteousness of the faith which he had yet being uncircumcised: that he might be the father of all them that believe, though they be not circumcised; that righteousness might be imputed unto them also:

11. Et signum accepit circumcisionis, sigillum justitiæ fidei quæ fuerat in præputio; ut esset pater omnium credentium per præputium, quo ipsis quoque imputetur justitia;

12. And the father of circumcision to them who are not of the circumcision only, but who also walk in the steps of that faith of our father Abraham, which he had being yet uncircumcised.

12. Et pater circumcisionis, non iis qui sunt ex circumcisione tantum, sed qui insistunt vestigiis fidei, quæ fuit in præputio patris nostri Abrahæ.