I will both lay me down in peace, and sleep (comp. Psalms 3:5). His confidence in God enables David to lay himself down calmly and tranquilly to sleep, whatever dangers threaten him. He seeks his couch, and at once ( יחדּו) slumber visits him. No anxious thoughts keep him tossing on his bed for hours. For thou, Lord, only makest me dwell in safety. David has a satisfaction in thinking that it is God only who watches over him. All other help would be vain, superfluous. God alone brought Israel through the wilderness (Deuteronomy 32:12); God alone established Israel in Canaan (Psalms 44:2, Psalms 44:3). David feels that he needs no second helper and protector.
HOMILETICS