Psalms 31:16

16.Make thy face to shine upon thy servant. We have said formerly, and we shall see in many instances hereafter, that this form of speech is taken from the common apprehension of men, who think that God regards them not, unless he really show his care of them by its effects. According to the judgment of sense, afflictions hide his countenance, just as clouds obscure the brightness of the sun. David therefore supplicates that God, by affording him immediate assistance, would make it evident to him that he enjoyed his grace and favor, which it is not very easy to discern amidst the darkness of afflictions. Now, God is said to lift the light of his countenance upon us in two ways; either when he opens his eyes to take care of our affairs, or when he shows to us his favor. These two things are indeed inseparable, or rather, the one depends upon the other. But by the first mode of speech, we, according to our carnal conceptions, attribute to God a mutability which, properly speaking, does not belong to him: whereas the second form of speech indicates, that our own eyes, rather than the eyes of God, are shut or heavy when he seems to have no regard to our afflictions. By the word preserve David explains what he meant by the former expression; but as there was at that time no way of safety apparent to him, he encourages himself to hope for it by setting before him the goodness of God.