Then will I also confess unto thee ... - If you can do all this, it will be full proof that you can save yourself, and that you do not need the divine interposition. If he could do all this, then it might be admitted that he was qualified to pronounce a judgment on the divine counsels and dealings. He would then show that he had qualifications for conducting the affairs of the universe.
Related Commentaries of Job 40:14
Job 40:14
14 Then will I also confess unto thee that thine own right hand can save thee.