His flesh is consumed away, through pain and pining sickness. That it cannot be seen; because there is none left to be seen; but he who before was fat and flourishing, is now become a mere skeleton. That were not seen, formerly, because they were covered with flesh and fat. But this clause, is and may be rendered thus, and his bones are broken, and are not seen; which is to be metaphorically understood.
Related Commentaries of Job 33:21
Job 33:21
21 His flesh is consumed away, that it cannot be seen; and his bones that were not seen stick out.