John Gill Commentary Job 33:12

"Behold, I will answer thee, in this thou art not just; For God is greater than man." — Job 33:12 (ASV)

Behold, [in] this you are not just
Here begins Elihu's answer, who does not deny that Job was a just man, both before God in an evangelic sense, and before men in a moral sense; he did not go about to detract from Job's general character, as a man that lived soberly, righteously, and godly in the world; but in this he was not just, nor is it to be justified, with respect to this thing, he could not acquit him of doing what was wrong; namely, insisting so much on his own innocence, and tacking therewith such unbecoming and undue reflections on the dealings of God with him; he did not give to God his due, he did not do him justice in representing him in this light; he did not say nor do the right thing, so Mr. Broughton translates the words,``lo, here you are not in the right;'' see (Job 32:2) ;

I will answer thee ;
or "I must tell thee"; as the same writer renders the words, being able to make it clear and plain:

that God is greater than man :
than any man, than the greatest of men, most famous for power, wisdom, or justice; he is not only greater in his power, faithfulness, goodness, grace, and mercy, but in his holiness and righteousness, wisdom and knowledge; and therefore can never do either an unjust thing, or an unwise one; and for man, who is both sinful and ignorant, even the best in comparison of him, to arraign him at his bar, is very arrogant and presumptuous; since he knows best what to do, and what are his reasons for so doing, and is righteous in all his ways, and holy in all his works.