Charles Ellicott Commentary Job 15

Should a wise man utter vain knowledge ... —Job therefore is not wise, and his words have been vain and windy.

Should he reason with unprofitable talk? —No, his arguments, though pretentious and apparently recondite, are unprofitable, and can do no good.

Yea, thou castest off fear. —The tendency also of Job has been to encourage a kind of fatalism (e.g.,Job 12:16–25), and therefore to restrain the offering of prayer to God, besides setting an example which, if followed, as was likely from Job’s position, would lead to murmuring and blasphemy.

Your mouth utters your iniquity. — These words may mean either that “Your mouth teaches your iniquity,” or that “Your iniquity teaches your mouth.” If the former, the second clause of the verse is taken adversatively, meaning: “Your mouth proclaims your iniquity, though you choose the tongue of the crafty, and so you contrive in some degree to conceal it.” If the latter, the second clause is understood as a consequence: “Your iniquity teaches your mouth its eloquence, and as a consequence, you choose the tongue of the crafty.” We incline to the latter, though it is fair to say that the next verse seems rather to favor the other meaning.

Art thou the first man that was born? — This is a retort upon Job 12:2, Job 12:7, Job 12:9, where Job had claimed equal knowledge for the inanimate creation.