Job 4:7 - Ellicott's Commentary On The Whole Bible

Remember, I pray thee, who ever perished, being innocent? — He challenges Job’s experience, and quotes his own in proof of the universal connection between sin and suffering. In so doing, his object may be to insinuate that Job is sinful; or, as seems perhaps more probable, and certainly more gracious, to prove to him that if he is what he was supposed to be, that itself is a ground of hope, inasmuch as no innocent person is allowed to perish. He utters here a half-truth, which, however, is after all true, inasmuch as God will never fail, though He may try, those who trust in Him.