John Wesley on 1 Samuel 21:11

King of the land - Of Canaan. They call him king, either more generally for the governor, the most eminent captain and commander, or, as the king elect, the person designed to be king: for, by this time, the fame of Saul's rejection, and David's destination to the kingdom, was got abroad among the Israelites, and from them, probably to the Philistines. Did they not sing, &c. - And therefore consider what to do; and now our great enemy is in thy hand, be sure thou never let him go alive.