He will not allow your foot to be moved: he that keeps you will not slumber.
All Commentaries on Psalms 121:3 Go To Psalms 121
Augustine of Hippo
AD 430
2. Sing therefore what followeth; if thou wish to hear how thou mayest most securely set thy feet on the steps, so that thou mayest not be fatigued in that ascent, nor stumble and fall: pray in these words: "Suffer not my foot to be moved!" (ver. 3). Whereby are feet moved; whereby was the foot of him who was in Paradise moved? But first consider whereby the feet of him who was among the Angels were moved: who when his feet were moved fell, and from an Angel became a devil: for when his feet were moved he fell. Seek whereby he fell: he fell through pride. Nothing then moveth the feet, save pride: nothing moveth the feet to a fall, save pride. Charity moveth them to walk and to improve and to ascend; pride moveth them to fall ...Rightly therefore the Psalmist, hearing how he may ascend and may not fall, prayeth unto God that he may profit from the vale of misery, and may not fail in the swelling of pride, in these words, "Suffer not my feet to be moved!" And He replieth unto him, "Let him that keepeth thee not sleep." Attend, my beloved. It is as if one thought were expressed in two sentences; the man while ascending and singing "the song of degrees," saith, "Suffer not my foot to be moved:" and it is as if God answered, Thou sayest unto Me, Let not my feet be moved: say also, "Let Him that keepeth thee not sleep," and thy foot shall not be moved.
