When he is about to fill his belly - Or rather, “there shall be enough to fill his belly.” But what “kind” of food it should be, is indicated in the following part of the verse. “God” would fill him with the food of his displeasure. It is spoken sarcastically, as of a gormandizer, or a man who lived to enjoy eating, and the meaning is, that he should for once have enough. So Rosenmuller interprets it.
God shall cast the fury - This is the kind of food that he shall have. God shall fill him with the tokens of his wrath - and he shall have enough.
And shall rain it upon him while he is eating - Noyes renders this, “And rain it down upon him for his food.” The meaning is, that God would pour down his wrath like a plentiful shower while he was in the act of eating. In the very midst of his enjoyments God would fill him with the tokens of his displeasure. There can be no doubt that Zophar designed that this should be understood to be applicable to Job. Indeed no one can fail to see that his remarks are made with consummate skill, and that they are such as would be fitted “to cut deep,” as they were doubtless intended to do. The speaker does not, indeed, make a direct application of them, but he so makes his selection of proverbs that there could be no difficulty in perceiving that they were designed to apply to him, who, from such a height of prosperity, had been so suddenly plunged into so deep calamity.