The Hebrew negative here employed, ’al, used also in the expression “will not slumber,” makes the verse an expression of a wish or a petition: “May he not suffer thy foot to be moved: may he that keepeth thee not slumber.” These words were possibly sung by one band of pilgrims with another band responding in effect, “Nay there is no need for such a prayer, for He that keepeth Israel neither slumbers nor sleeps; Israel’s Watchman will not be caught off guard, like a human sentinel on a city wall.” God’s vigilance is unwearied. The Eternal is never exhausted and is always attentive to the needs of His earthly children.