Romans 4:4

(4) This, then (the righteousness attributed to Abraham), was an act of grace on the part of God, and not of merit on the part of man. It therefore carries with it no ground of boasting.The proposition is put in a general form. Those who base their claim on works have a right to their reward. It is not conceded to them by any sort of imputation, but is their desert. On the other hand (Romans 4:5), those who rely only upon faith, even though ungodly themselves, have righteousness imputed to them. This latter was Abraham’s case, and not the former. (The specific application to Abraham is not expressed, but implied.)

The reward.—Literally, his wages. The relation between what he receives and what he does is that of wages for work done. He can claim it, if need be, in a court of law. There is in it no element of grace, or favour, or concession.