1 Samuel 31:9
And they cut off his head, and stripped off his armour, and sent into the land of the Philistines round about, to publish it in the house of their idols, and among the people. And they cut off his head, and stripped off his armour, and sent into the land of the Philistines round about, to publish it in the house of their idols, and among the people.
The verse comes after Saul shook with fear as the Philistine army massed at Shunem while Israel pitched camp by Mount Gilboa. In that moment he stood alone and without defense because God had left him. That forsaken dread stands opposite to Gideon, who advanced to battle in reliance upon God.
The Philistines then severed Saul's head and stripped away his armor to hold them as trophies of their victory. Those spoils were carried round about through the Philistine country to proclaim the triumph both to the populace and inside the houses of idols. His armor was set up in the house of Ashtaroth, and his head was fastened up in the temple of Dagon. By that exhibition the victory was ascribed to false gods, and dishonor was cast upon Jehovah.