Romans 11:35

Or who hath ... - The sentiment in this verse is found substantially in Job 41:11. “Who hath prevented me, that I should repay him.” The Hebrew word “prevented” means to anticipate, to go before; and God asks who has anticipated me; who has conferred favors on me before I have on him; who has thus laid me under obligation to him.” This is the sense in which the apostle uses the word here. Who has, by his services, laid God under obligation to recompense or pay him again? It is added in Job, “Whatsoever is under the whole heaven is mine.” Thus Paul, contrary to the prevailing doctrine of the Jews, shows that no one could plead his own merits, or advance with a claim on God. All the favors of salvation must be bestowed by mercy or grace. God owned them all; and he had a right to bestow them when and where he pleased. The same claim to all things is repeatedly made by God; Exodus 19:5; Deuteronomy 10:14; Psalms 24:1; Psalms 50:12.

Shall be recompensed - Repaid as a matter of debt. None of God’s mercies can be conferred in that way; if they could, man could bring God under obligation, and destroy the freeness and benevolence of his favors.