1 Samuel 31:1-3
31 Meanwhile the Philistine and Israelite armies had clashed. The men of Israel ran away, but many of them were killed on the heights of Gilboa. 2 The Philistines even followed Saul and his sons and closed in on them; there they killed his sons, Jonathan (the beloved friend of David), Abinadab, and Malchi-shua.
Notice that David does not participate in the battle against his own people, and that even while he lives among the Philistines hiding from Saul, he doesn’t serve them. This expedition against the raiding Amalekites offers a powerful explanation both for why David doesn’t fight for the Philistine king and why he doesn’t fight to preserve the armies of Israel. Because David is far away with his own desperate battles to fight, no shame falls on him for any oaths he might have broken.
3 The battle closed in around Saul, and he was shot with arrows and badly wounded.Read full chapter