His flesh is consumed away, that it cannot be seen - He wastes away. His flesh, once vigorous, beautiful, and fair, now disappears. This is not a mere description of the nature of his sickness, but it is a description of the disciplinary arrangements of God. It is an important part of his affliction, as a part of the discipline, that his flesh vanishes, and that his appearance is so changed that he becomes repulsive to the view.
And his bones that were not seen, stick out - His bones were before invisible. They were carefully concealed by the rounded muscle, and by the fat which filled up the interstices, so that they were not offensive to the view. But now the protuberances of his bones can be seen, for God has reduced him to the condition of a skeleton. This is one of the common effects of disease, and this shows the strength of the discipline which God contemplates. The parts of the human frame which in health are carefully hid from the view, as being unsightly, become now prominent, and can be hidden no longer. One design is to humble us; to take away the pride which delighted in the round and polished limb, the rose on the cheek, the ruby lip, and the smooth forehead; and to show us what we shall soon be in the grave.

His flesh is consumed away - As in atrophy, marasmus, and consumptive complaints in general.

His flesh is consumed away, that it cannot be seen,.... All being gone, none left to be seen, nothing but skin and bones; and this partly through the vehemence of strong pain, and partly through the nausea of food; not being able to take anything for nourishment and the support of the fluids, and so quite emaciated:
and his bones that were not seen stick out: which before were covered with flesh and fat, so that they could not be seen; but now the flesh and fat being wasted, they seem as if they rose up in an eminence, and stood out to be beheld; this was also Job's case, being reduced to a mere skeleton, Job 19:20. Elihu, in this description of an afflicted man, seems to have Job chiefly in view, and by this would intimate to him that God had been, and was speaking to him by those afflictions, which he would do well to advert unto.

His flesh once prominent "can no more be seen." His bones once not seen now appear prominent.
stick out--literally, "are bare." The Margin, Hebrew (Keri) reading. The text (Chetib) reads it a noun "(are become) bareness." The Keri was no doubt an explanatory reading of transcribers.

The contracted future form יכל, again, like ישׂם, Job 33:11, is poetic instead of the full form: his flesh vanishes מראי, from sight, i.s. so that it is seen no longer; or from comeliness, i.e., so that it becomes unsightly; the latter (comp. 1-Samuel 16:12 with Isaiah 53:2, ולא־מראה) might be preferred. In Job 33:21 the Keri corrects the text to ושׁפּוּ, et contrita sunt, whereas the Chethib is to be read וּשׁפי, et contritio. The verb שׁפה, which has been explained by Saadia from the Talmudic,
(Note: He refers to b. Aboda zara 42a: If a heathen have broken an idol to pieces (שׁפּה) to derive advantage from the pieces, both the (shattered) idol and the fragments (שׁפּוּיין) are permitted (since both are deprived of their heathenish character).)
signifies conterere, comminuere; Abulwald (in Ges. Thes.) interprets it here by suhifet wa-baradet, they are consumed and wasted away, and explains it by כּתּתוּ. The radical notion is that of scraping, scratching, rubbing away (not to be interchanged with Arab. sf', ספה, which, starting from the radical notion of sweeping away, vanishing, comes to have that of wasting away; cognate, however, with the above Arab. sḥf, whence suhâf, consumption, prop. a rasure of the plumpness of the body). According to the Keri, Job 33:21 runs: and his bones (limbs) are shattered (fallen away), they are not seen, i.e., in their wasting away and shrivelling up they have lost their former pleasing form. Others, taking the bones in their strict sense, and שׁפה in the signification to scrape away = lay bare, take לא ראו as a relative clause, as Jeremiah. has done: ossa quae tecta fuerant nudabuntur (rather nudata sunt), but this ought with a change of mood to be לא ראו...וישׁפּוּ. To the former interpretation corresponds the unexceptionable Chethib: and the falling away of his limbs are not seen, i.e., (per attractionem) his wasting limbs are diminished until they are become invisible. ראוּ is one of the four Old Testament words (Genesis 43:26; Ezra 8:18; Leviticus 23:17) which have a Dagesh in the Aleph; in all four the Aleph stands between two vowels, and the dageshing (probably the remains of a custom in the system of pointing which has become the prevailing one, which, with these few exceptions, has been suffered to fall away) is intended to indicate that the Aleph is here to be carefully pronounced as a guttural (to use an Arabic expression, as Hamza), therefore in this passage ru-'û.
(Note: Vid., Luzzatto's Grammatica della Lingua Ebraica (1853), 54. Ewald's (21) view, that in these instances the pointed Aleph is to be read as j (therefore ruju), is unfounded; moreover, the point over the Aleph is certainly only improperly called Dagesh, it might at least just as suitably be called Mappik.)
Thus, then, the soul (the bearer of the life of the body) of the sick man, at last succumbing to this process of decay, comes near to the pit, and his life to the ממתים, destroying angels (comp. Psalm 78:49; 2-Samuel 24:16), i.e., the angels who are commissioned by God to slay the man, if he does not anticipate the decree of death by penitence. To understand the powers of death in general, with Rosenm., or the pains of death, with Schlottm. and others, does not commend itself, because the Elihu section has a strong angelological colouring in common with the book of Job. The following strophe, indeed, in contrast to the ממיתים, speaks of an angel that effects deliverance from death.