Albert Barnes Commentary Romans 4:4

"Now to him that worketh, the reward is not reckoned as of grace, but as of debt." — Romans 4:4 (ASV)

Now to him that worketh, etc. This passage is not to be understood as affirming that any actually have worked out their salvation by conformity to the law so as to be saved by their own merits; but it expresses a general truth regarding works. On that plan, if a man were justified by his works, it would be a matter due to him.

It is a general principle regarding contracts and obligations that when a man fulfills them, he is entitled to the reward as that which is due to him and which he can claim. This is well understood in all transactions among men. When a man has fulfilled the terms of a contract, to pay him is not a matter of favor; he has earned it, and we are bound to pay him.

So, says the apostle, it would be thus: if a man were justified by his works, he would have a claim on God. It would be wrong not to justify him. And this is an additional reason why the doctrine cannot be true .

The reward. The pay, or wages. The word is commonly applied to the pay of soldiers, day-laborers, etc. (Matthew 20:8; Luke 10:7; 1 Timothy 5:18; James 5:4). It has a similar meaning here.

Reckoned. Greek, Imputed. This is the same word which, in Romans 4:3, is rendered counted, and in Romans 4:22, imputed. It is used here in its strict and proper sense, to reckon that as belonging to a man which is his own, or which is due to him.

Of grace. Of favor; as a gift.

Of debt. As due; as a claim; as a fair compensation according to the contract.