For you have girded me with strength unto the battle: you have subdued under me those that rose up against me.
Read Chapter 18
Augustine of Hippo
AD 430
40. "And Thou hast girded me with strength to the war" (ver. 39). And the loose desires of my flesh hast Thou bound up with strength, that in such a fight I may not be encumbered. "Thou hast supplanted under me them that rose up against me." Thou hast caused them to be deceived, who followed upon me, that they should be brought under me, who desired to be over me.
Against. me. No prince was ever more courageous than David, as the single combat with Goliath evinces. We know not that he ever lost a battle. He refers all the glory to God. (Calmet)