Albert Barnes Commentary Psalms 3:5

"I laid me down and slept; I awaked; for Jehovah sustaineth me." — Psalms 3:5 (ASV)

I laid me down and slept - Despite these troubles and dangers, I had such confidence that God hears prayer, and such calm trust in His protection, that I lay down gently and slept securely. The psalmist mentions this as a remarkable proof of divine protection and favor. He was driven from his capital, his throne, and his home. He was compelled to wander as a poor fugitive, accompanied by only a few friends. He was pursued by enemies, who numbered in the thousands. He was made an exile, and persecuted by his own son; and with this son were men of age and experience in war.

The forces of his enemies might come upon him at any moment. In these circumstances—persecuted as he was, and under all the anxiety and distress he felt from his own son's ungrateful conduct—he considered it a unique proof of divine favor that on such a dreadful night he was allowed to lie down calmly and sleep.

This experience also illustrates the peace that confidence in God gives to those who trust in Him. Indeed, it can be seen here as a testament to the unspeakable value of divine favor and a demonstration of how trusting God brings calmness and peace of mind in times of trouble. (Psalms 127:2).

I awaked - Still safe and secure. He had not been suddenly attacked by his foes, and made to sleep the sleep of death; he had not been crushed by anguish of spirit. That we are awaked in the morning after a night’s refreshing slumber, that we are raised up again to the enjoyments of life, that we are permitted again to greet our friends and to unite with them in the privileges of devotion—all this should always be regarded as a new proof of God’s goodness and should lead to acts of praise. We have no power to awaken ourselves; and when we remember how many are taken away from our world each night—how many lie down to sleep, only to wake no more—we should never rise from a bed of repose without giving our first thoughts in gratitude to our Great Preserver.

For the Lord sustained me - He kept me from danger; He preserved me from death. And it is as true now as it was then, that God is the supporter of life when people sleep. He guards us; He causes the heart’s action to continue as it propels the blood through our bodies; He secures the gentle heaving of the lungs, both when we slumber and when we wake.