1 Samuel 23:8

To besiege David. In his efforts against David, Saul was probably convinced that God was leading him. A man can think evil so long that it becomes good in his eyes, and he can be conscientious in carrying out the thoughts and intents of his heart. For example, Korah felt convinced that God had appointed him to lead in the rebellion against Moses; Miriam was confident of right when she criticized the wife of Moses; and Jehoiakim, apparently without any qualms, refused to accept Jeremiah’s prophecy of Israel’s Babylonian captivity and burned the prophetic scroll (Jeremiah 36:22-30).

David, on the contrary, had in his heart the desire to maintain the justice and dignity of his people before neighboring tribes, as well as to assist any in Israel who might be suffering hardship. He was not revolting against Saul by ingratiating himself with members of his own tribe. Neither was he fighting, as the Philistines were doing, for the booty obtainable by raiding towns in nearby districts.