Theophylact of Ohrid

He is also the source of all good things, and whatever He gives, He gives not as one obligated to repay, like someone who has received something from another, but out of His own goodness. For "who has first given to Him," that is, to God, that it should be repaid to him? That is, so that the benefaction bestowed by God might be considered a repayment to the one who gave?

Commentary on Romans ↗

Thomas Aquinas

Second, he shows the excellence of divine wisdom according as it has height in itself, and indeed is that height which is the supreme principle. Two points pertain to this: first, that it does not proceed from something else; second, that other things proceed from it, at for from him. That God's wisdom does not depend on a higher source is shown in two ways. First, by the fact that it is not instructed by someone else's teaching. Hence, he says: or who has been his counselor? As if to say: no one. …

Commentary on Romans ↗

Bonaventure

Therefore when it condemns and reprobates, it operates according to justice: but when it predestines, according to grace and mercy, which does not exclude justice. Because therefore all, insofar as they were of the mass of perdition, deserved to be condemned: therefore more are reprobated than chosen, so that it may be shown that salvation is according to special grace, but damnation according to common justice. …

Breviloquium ↗