Arise, O LORD; save me, O my God: for you have smitten all my enemies on the cheek bone; you have broken the teeth of the ungodly.
This shows that David's expectation of victory was not in himself, in his personal prowess as a warrior, but in the faithfulness of the Lord his God. Hence his impassioned cry, "Arise, O Lord! save me, O my God!" It is true that David marshalled his forces as a skilful and experienced general should, and as carefully as if everything in the battle to ensue was to be accomplished by the sword alone; — and yet he still looked to God alone for success. And to inspire himself with confidence that God would give success, he refers to the victories He had given him in times past, saying, "Thou hast smitten all mine enemies upon the cheek bone; thou hast broken the teeth of the ungodly." This imagery of breaking the cheek bone and teeth of enemies is likening them to wild beasts whose great power is in their jaws and teeth, so that when their jaws and teeth are broken their power to injure is gone. The imagery, then, indicates that the Lord had always destroyed the power of David's enemies to injure him. And as the Lord had subdued his enemies before him hitherto, David could not but believe that He would subdue them still. This, his belief, was not in vain, as the speedy winding up of Absalom's rebellion showed; for Absalom's forces, though outnumbering his father's probably more than ten to one, were utterly routed and dispersed, and himself slain, in the first and only battle fought. The battle was the Lord's, the victory His, and to Him David ascribes it.
(David Caldwell, A. M.)
Parallel VersesKJV: Arise, O LORD; save me, O my God: for thou hast smitten all mine enemies upon the cheek bone; thou hast broken the teeth of the ungodly.