John Gill's Exposition of the Whole Bible
Job 20:15
He hath swallowed down riches,.... Not his own, but another's, which he has spoiled him of and devoured, with as much eagerness, pleasure, and delight, as a hungry man swallows down his food; having an excessive and immoderate love of riches, and an insatiable desire after them, which make him stop at nothing, though ever so illicit, to obtain them; and when he has got them into his possession, thinks them as safe as the food in his belly, and never once dreams of refunding them, which yet he must do, as follows:
and he shall vomit them up again; that is, make restoration of them, not freely, but forcedly, with great reluctance, much pain of mind, and gripes of conscience:
God shall cast them out of his belly; he shall oblige him to cast them up again, by working upon his heart, making his mind uneasy, loading his conscience with guilt, so that he shall have no rest nor peace until he has done it; though they are as meat in his belly within him, they shall not remain with him; though they are in his house, in his coffers, or in his barns, they shall be fetched out from thence.