John Wesley on Job 33:9

Clean - Not absolutely, for he often confesses himself to be a sinner, but no such transgression, as might give God just occasion to punish him so severely, as is implied, where he blames God for finding occasions against him, implying that he had given him none by his sins. And thus far Elihu's charge was just, and herein it differs from the charge of Job's three friends, who often accuse him, for asserting his own innocency; although they did it, because they thought him an hypocrite, whereas Elihu does it upon other grounds, even because Job's justification of himself was accompanied with reflections upon God.