Paul does not expect an answer to his question. He is using the question to correct the conclusion that God is unrighteous. (See: [[rc://en/ta/man/translate/figs-rquestion]])
"That is not possible!” or "Certainly not!" This expression strongly denies that this could happen. You may want have a similar expression in your language that you could use here.
## For he says to Moses, ##
"For God says to Moses,"
## it is not because of him who wills, nor because of him who runs, ##
"it is not because of what people want or because they try hard,"
## nor because of him who runs ##
Paul compares someone running a race to someone who is trying hard to get to a goal. (See: [[rc://en/ta/man/translate/figs-metaphor]])