The king of the land— The generality of interpreters suppose, either that the Philistines knew that David should succeed Saul in the kingdom, or that by the word king is meant chief or general. See Deuteronomy 33:5.
Related Commentaries of 1 Samuel 21:11
1 Samuel 21:11
11 And the servants of Achish said unto him, Is not this David the king of the land? did they not sing one to another of him in dances, saying, Saul hath slain his thousands, and David his ten thousands?