Albert Barnes Commentary Job 31:14

"What then shall I do when God riseth up? And when he visiteth, what shall I answer him?" — Job 31:14 (ASV)

What then shall I do when God riseth up? - That is, when he rises up to pronounce sentence upon people, or to execute impartial justice. Job admits that if he had done injustice to a servant, he would have reason to dread the divine indignation, and that he could have no excuse. “I tremble,” said President Jefferson, speaking of slavery in the United States, “when I remember that God is just!” Notes on Virginia.

And when he visiteth - When he comes to inspect human conduct. Umbreit renders it “when he punishes.” The word visit is often used in this sense in the Scriptures.