John Calvin on Romans 3:30

30. Who shall justify, The future is used for the present — “who justifies,” after the manner of the Hebrew language, though some consider that the day of judgment is referred to; but he seems to speak of a present act, or as Grotius says, of a continued act, which the Hebrews expressed by the future tense. — Ed. etc. In saying that some are justified by faith, and some through faith, he seems to have indulged himself in varying his language, while he expresses the same thing, and for this end, — that he might, by the way, touch on the folly of the Jews, who imagined a difference between themselves and the Gentiles, though on the subject of justification there was no difference whatever; for since men became partakers of this grace by faith only, and since faith in all is the same, it is absurd to make a distinction in what is so much alike. I am hence led to think that there is something ironical in the words, as though be said, — “If any wishes to have a difference made between the Gentile and the Jew, let him take this, — that the one obtains righteousness by faith, and the other through faith.”

But it may be, that some will prefer this distinction, — that the Jews were justified by faith, because they were born the heirs of grace, as the right of adoption was transmitted to them from the Fathers, — and that the Gentiles were justified through faith, because the covenant to them was adventitious.

Romans 3:31

31. Do we then make void the law through faith? God forbid: yea, we establish the law.

31. Legem igitur irritam facimus per fidem? Ne ita sit: sed Legem stabilimus.