Psalms 3:4,5 - Joseph Benson’s Commentary on the Old and New Testaments

I cried unto the Lord with my voice By prayer I commended myself to the divine protection; and he heard me out of his holy hill Out of heaven, so called Psalms 15:1. I laid me down and slept Securely, casting all my cares upon God. I awaked As after a sweet and undisturbed sleep, as though no danger had been near me. “It was an argument of settled courage, and shows the unspeakable advantage of a true and genuine confidence in God, that David was able, in such distressing and dangerous circumstances, thus to lie down, calmly sleep, and wake in peace. But what cannot that man do who is sustained of God, propped up by him, as the word יסמכני, jesmecheni, properly signifies, by inspiring his mind with confidence and courage.” Chandler. But let it be remembered, this peace and serenity were the effects of pardoning love, and not experienced by him till, in consequence of genuine repentance for his foul transgressions, he was made a partaker of forgiveness, and tasted that the Lord is gracious: see Psalms 32:3-5.