Behold, he that keepeth Israel shall neither slumber nor sleep. He that kept Israel or Jacob, when asleep, and appeared to him in a dream, and promised to keep him in all places, and did; who found his posterity in the wilderness, and kept them as the apple of his eye: he keeps his spiritual Israel, whom he has chosen, redeemed, and calls; and he that is in general their keeper, is the keeper of every particular believer, who may promise themselves the utmost safety under his care; since, though he may sometimes seem to sleep, when he withdraws his gracious presence, defers help, and does not arise so soon to the assistance of his people as they wish for and expect; yet does not in reality sleep, nor is any ways negligent of them; no, not so much as slumber, nor is in the least indifferent about them, and careless of them; see Ge 28:15.
So Homer represents Jupiter as not held by sleep, while other gods and men slept all night; and hence Milton has the phrase of "the unsleeping eyes of God": but the Phrygians had a notion that their god slept in winter, and was awake in summer .
Iliad. 2. v. 1, 2. Paradise Lost, B. 5. v. 647. Plutarch. de Iside & Osir.