Charles H. Spurgeon on Psalms 119:83

For I am become like a bottle in the smoke, etc. Satan can afflict the body by the mind. For these two are so closely bound together that their good and bad estate is shared between them. If the heart be merry the countenance is cheerful, the strength is renewed, the bones do flourish like an herb. If the heart be troubled, the health is impaired, the strength is dried up, the marrow of the bones wasted, etc. Grief in the heart is like a moth in the garment, it insensibly consumeth the body and disorders it. This advantage of weakening the body falls into Satan's hands by necessary consequence, as the prophet's ripe figs, that fell into the mouth of the eater. And surely he is well pleased with it, as he is an enemy both to body and soul. But it is a greater satisfaction to him, in that as he can make the sorrows of the mind produce the weakness and sickness of the body; so can he make the distemper of the body (by a reciprocal requital) to augment the trouble of the mind. How little can a sickly body do? it disables a man for all services; he cannot, oft pray, nor read, nor hear. Sickness takes away the sweetness and comfort of religious exercises; this gives occasion for them to think the worst of themselves; they think the soul is weary of the ways of God when the body cannot hold out. Richard Gilpin, in "A Treatise of Satan's Temptations, "1677.