He wilt not suffer thy foot to be moved
This is either an address of the psalmist to his own soul; or to any other good man, his friend and acquaintance, assuring of stability, and of final perseverance in grace to glory. The Lord keeps the feet of his saints from falling: he will not suffer them to be moved out of the spiritual estate in which they stand; nor off of the Foundation and Rock of ages, on which their feet are set, and their goings established; nor out of the house of God, where they are as pillars; nor out of his ways, where he upholds their goings; moved in some sense they may be, yet not "greatly moved"; their feet may be "almost" gone, and their steps "well nigh" slipped, and yet shall not fall finally and totally, or so as to perish; see ( Psalms 62:2 ) ( 73:2 ) ( 37:24 ) ;
he that keepeth thee will not slumber;
neither angels nor men are the keepers of the saints, but the Lord himself; he is the keeper of every individual saint, of every regenerate person, of everyone of his sheep, of every member of his church; he keeps them by his power, he preserves them by his grace, he holds them with his right hand; guides them by his counsel, keeps their feet from falling, and brings them safe to glory: and a watchful keeper he is, he does not so much as slumber; he keeps them night and day, lest any harm them, ( Isaiah 27:3 ) . Gussetius reads the whole as a prayer, "let him not suffer [thy foot]", &c. "let not thy keeper slumber" F9; to which the answer follows.
F9 (Mwny la-Nty la) "ne permittat--ne dormitet", Junius & Tremellius, Piscator; so Ainsworth.