Albert Barnes Commentary Psalms 144:10

"Thou art he that giveth salvation unto kings; Who rescueth David his servant from the hurtful sword." — Psalms 144:10 (ASV)

It is he that giveth salvation unto kings - Margin, “Victory.” The Hebrew word means “salvation,” but it is used here in the sense of deliverance or rescue. Even “kings,” with all their armies, have no hope but in God. They seem to be the most powerful of men, but they are, like all other people, wholly dependent on him for deliverance from danger.

David thus recognizes his own entire dependence. Though a king in the divine purpose and in fact, he had no power except as derived from God; he had no hope of deliverance but in him. It is implied further that God might be considered just as willing to intervene on behalf of kings as of other people when their cause was right, and when they looked to him for aid. See the notes at (Psalms 33:16): there is no king saved by the multitude of an host. Compare (Psalms 44:5–6).

Who delivereth David his servant from the hurtful sword - Who has done it; who can do it again; on whom alone David is dependent as all other men are. David speaks of himself by name elsewhere. See (Psalms 18:50); (2 Samuel 7:26). He refers to himself also under the name of “the king,” (Psalms 61:6); (Psalms 63:11). Caesar, in his writings, often speaks of himself in the same way.