These notes are based on the NASB text.

What is the background of Psalm 121?
Psalm 121 is a Song of Ascents which pictures God’s care, protection, and vigilant watchcare. Some scholars suggest that pilgrims sang it en route to Jerusalem and its Temple.

121:1   I will lift up my eyes to the mountains;
From whence shall my help come?
121:2   My help comes from the Lord,
Who made heaven and earth.

When the psalmist felt threatened by danger he lifted his eyes to the mountains and beyond to the One who created the mountains. The question asked in verse 1 is answered in the verses that follow. He acknowledged that his help came from the Lord, not from the mountains.

121:3   He will not allow your foot to slip;
He who keeps you will not slumber.
121:4   Behold, He who keeps Israel
Will neither slumber nor sleep.

The Lord, unlike man, is a reliable source of help. He gives sure footing when the path is narrow and treacherous. He is always on watch. He never slumbers nor sleeps like human sentries. Recall also that Elijah accused Baal of sleeping in the encounter on Mount Carmel recorded in 1 Kings 18:27.

Practical Consideration: We can sleep knowing that God is awake.
It is often the case that when we are experiencing demanding and difficult circumstances we lose sleep. It is at those times that sleep seems to escape us. We lie in bed staring at the ceiling as millions of anxious thoughts race across our hearts and minds. We play out dozens of scenarios as we long for a solution to our very present troubles. As a consequence we become increasingly tired and our perspective and patience slowly begins to ebb away. We begin to long for the peaceful sleep known to children.

The Psalms offer an important message to those who long for sleep in the midst of life’s anxious times. In Psalm 121:3b-4 we are told, “[God] who keeps you will not slumber. Behold, He who keeps Israel will neither slumber nor sleep.” There is a very simple message here: God never sleeps, slumbers or naps. God is awake when we are asleep.

And so, when we find ourselves in the midst of difficult circumstances that are robbing us of much needed sleep, we should turn the matter over to God when we go to bed because He will be awake all night anyway! We must learn to trust the Lord in the light of day and in the deepest darkness of night. Only then will we be able to say along with David, “In peace I will both lie down and sleep, For Thou alone, O Lord, dost make me to dwell in safety” (Psalm 4:8).

121:5   The Lord is your keeper;
The Lord is your shade on your right hand.
121:6   The sun will not smite you by day,
Nor the moon by night.

The Lord offers protection from the elements, particularly the debilitating effects of sunstroke and moonstroke. The psalmist was familiar with the effects of the sun on man and beast in the arid climate of Israel. Regarding moonstroke, the ancients thought this to be harmful. In fact, the word lunatic, used to describe the insane, came from this belief (see also Matthew 17:15). Some suggest that the psalmist had in mind the protection of God from the heat of the sun by day and the sudden cold that came at night. Verse 6 also defines the scope of God’s protective care. . .it continues both day and night. In Hebrew literature, a way of expressing totality was by naming a pair of opposites (“sun” and “moon” or “day” and “night”) to include everything between (see also Psalm 91:5-6). These opposites may also suggest the known and seen dangers of the day and the unknown and unseen dangers of the night.

Practical Consideration: God stands ready to protect us around the clock.
God’s protective care is available twenty-four hours a day. He watches over us in the daytime and protects us from dangers we can see. He watches over us in the night from dangers that we cannot see. We need God’s protection because we are vulnerable both day and night.

121:7   The Lord will protect you from all evil;
He will keep your soul.

The Lord offers protection from evil (see also Matthew 6:13). This is not a reference to a cushioned life, but a well-armed one. The word “all” stresses the fullness of God’s protective power and care.

121:8   The Lord will guard your going out and your coming in
From this time forth and forever.

The Lord offers protection through the daily course of life’s enterprises and events and forever. C.H. Spurgeon comments, “None are so safe as those whom God keeps; none so much in danger as the self-secure.

Practical Consideration: The fact of God’s vigilant care should inspire confidence.
We can face all of life’s issues with confidence because God is always on the job. He never falls asleep on the job. He never abandons His post. He never grows tired or weary. The great Creator of the universe personally watches over His own.