דברי הימים א, פרק י׳, פסוק ח׳

The aftermath of war often waits for the light of day. As night fell, the decisive clash came to a close, since continuing to fight in the darkness offered no advantage. Because of this, the Philistine forces only returned to the battlefield the following morning. Their objective was to strip the fallen soldiers, removing their clothing and gathering any valuables as spoils of war, a standard military practice throughout history [מצודת ציון, ביאור שטיינזלץ].

As they moved across the mountain looting the bodies, the Philistines made a completely unexpected discovery. They found Saul and his sons lying dead among the casualties. The Philistines were entirely surprised by this sight, as they had assumed the Israelite king would use the cover of night to slip away and escape. They never imagined that he would remain on the battlefield, staying until the bitter end [ביאור שטיינזלץ].