This simple but exquisite little hymn of four fourline verses, dwells almost exclusively on the sleepless guardianship of His people by the (God who made the world. An implied contrast with the idols of the heathen, “peradventure sleeping,” while their votaries pray (1 Kings 18:27), is felt in every verse. (See Note Psalm 121:1.) But it is only implied. The poet seems to want nothing to heighten his truthful confidence, neither vivid colouring nor elaborate imagery, nothing save the repetition again and again of the one word keep. (See Notes.) What a history were that, if it could be written, of the countless thousands of Christians who have been consoled in trouble or sickness by this psalm! Among others, it was read at the deathbed of Julius Hare. It is in this psalm that the steplike progression of the rhythm is most plainly marked.
Title.—The Hebrew, in many editions, presents a variation from the usual “song of degrees.” Here, “a song for the degrees”—a variation which has been claimed in support of two rival theories, since it favours equally the view which make these hymns pilgrim songs, and that which sees in them a reference to the actual steps leading up to the Temple.
“In the mountains did he feel his faith
. . . . and there his spirit shaped
Shade.—An image of protection, and one peculiarly attractive to the Oriental. (See Numbers 14:9, margin; Psalm 91:1; Isaiah 25:4; Isaiah 32:2.)
Upon thy right hand.—Some commentators combine this expression with the figure of the shadow, supposing the psalmist, in the phrase “right hand,” to allude to the south or sunny side. But this is prosaic. No doubt there is here, as so often, a confused combination of metaphors. We have several times met with the figure of the right-hand comrade in war, a protection to the unshielded side (Psalm 16:8; Psalm 109:31, &c).
Nor the moon by night.—Possibly there is allusion to the belief, so common in old times, of the harmful influence of the moon’s light—a belief still recalled in the word lunacy. It is a fact that temporary blindness is often caused by moonlight. (See authorities referred to by Ewald and Delitzsch.) Others, again, think that the injurious cold of the night is here placed in antithesis to the heat of the noonday sun (comp. Genesis 31:40; Jeremiah 36:30), the impression that intense cold burns being common in the East, as indeed everywhere. Tennyson speaks of the moon being “keen with frost.” But it is also possible that the generally harmful effects of night air are intended.