Job 12:9

(9) Who knoweth not in all these that the hand of the Lord hath wrought this?—This is the only place in the dialogue parts of Job in which the sacred name of Jehovah is found, and Job’s very use of the word in such a context is the clearest evidence of the superior knowledge that he claims. No one of his friends makes use of the name; but Job uses it here, and shows thereby his knowledge of the covenant name.