Albert Barnes Commentary Job 34:12

"Yea, of a surety, God will not do wickedly, Neither will the Almighty pervert justice." — Job 34:12 (ASV)

Yea, surely God will not do wickedly - So important does Elihu hold this principle to be, that he repeats it and dwells upon it. He says, “it surely (אמנם 'omnâm) must be so.” The principle must be held at all hazards, and no opinion that contravenes this should be indulged for one moment. His ground of complaint against Job was that he had not held fast to this principle but, under the pressure of his sufferings, had indulged in remarks that implied that God might do wrong.

Neither will the Almighty pervert judgment - As Elihu supposed Job to have maintained . To “pervert judgment” is to do injustice; to place injustice in the place of right.