Charles H. Spurgeon on Psalms 13:3

"Lighten mine eyes, lest I sleep the sleep of death." In time of sickness and grief, the "eyes" are dull and heavy; and they grow more and more so as death approaches, which closes them in darkness. On the other hand, health and joy render the organs of vision bright and sparkling, seeming, as it were, to impart "light" to them from within. The words, therefore, may be fitly applied to a recovery of the body natural, and thence, of the body politic, from their respective maladies. Nor do they less significantly describe the restoration of the soul to a state of spiritual health and holy joy, which will manifest themselves in like manner, by "the eyes of the understanding being enlightened;" and in this case, the soul is saved from the sleep of sin, as the body is in the other, from the sleep of death. George Horne.