John Gill's Exposition of the Whole Bible
Job 20:23
[When] he is about to fill his belly,.... Either in a literal sense, when he is about to take an ordinary meal to satisfy nature; or in a figurative sense, when he is seeking to increase his worldly riches, and his barns and coffers, and endeavouring to get satisfaction therein:
[God] shall cast the fury of his wrath upon him; or "send it out on him" c; out of the treasures of it, which are laid up with him,
Deuteronomy 32:34; into his conscience, and fill him with a dreadful sense and apprehension of it, and that with great force and violence, and cast it, and pour it on him like fire, or any scalding liquor, which is very terrible and intolerable. This intends the indignation of God against sin, and his just punishment of it, according to the rigour of his justice; sometimes it is only a little wrath and displeasure he shows, he does not stir up all his wrath; but here it is threatened he will cast it, and pour it in great plenty, even "the fury" of it, in the most awful and terrible manner:
and shall rain it upon him while he is eating; signifying, that the wrath of God shall be revealed from heaven against him, from whence rain comes; that it shall fall on him from above, unseen, suddenly, and at an unawares, and come with a force and violence not to be resisted, and in great abundance and profusion. The allusion seems to be to the raining of fire and brimstone on Sodom and Gomorrah, the inhabitants of which were indulging themselves in gratifying the flesh, when that judgment came upon them, Luke 17:28; and so it was with the Israelites, when they sinned against God in the wilderness,
Psalms 78:30; perhaps Zophar may glance at Job's children being slain while they were eating and drinking in their elder brother's house, Job 1:18. Some render it, "upon his food" d; his meat, a curse going along with it, while he is eating it, his table becoming a snare unto him; or upon his wealth and riches, he is endeavouring to fill his belly or satisfy himself with; and others, "upon his flesh", as the Targum; or "into his flesh"; as Broughton, and so many of the Jewish commentators e meaning his body, filling it with diseases, so that there is no soundness in it, but is in pain, and wasting, and consuming; and Job's case may be referred to, his body being full of boils and ulcers.
c ישלח בו "mittet in eum", Pagninus, Montanus, Schmidt; so Mercerus, Piscator. d בלחומו "in cibum illius", Tigurine version. e Aben Ezra, Ben Gersom, Bar Tzemach; "in carne ejus", Pagninus, Montanus; "super carnem ejus", Beza; "in carnem ejus", Drusius, Mercer, Schmidt.