Jamieson, Fausset & Brown

The various terms used describe God as an object of the most implicit and reliable trust. rock--literally, "a cleft rock," for concealment. strength--a firm, immovable rock. horn of my salvation--The horn, as the means of attack or defense of some of the strongest animals, is a frequent emblem of power or strength efficiently exercised (compare Deu 33:17; Luk 1:69). tower--literally, "high place," beyond reach of danger.