1 Samuel 30:16-17

So he led David to them, and they found the Amalekites spread out across the fields, eating and drinking and dancing with joy because of the vast amount of plunder they had taken from the Philistines and the land of Judah. David and his men rushed in among them and slaughtered them throughout that night and the entire next day until evening. None of the Amalekites escaped except 400 young men who fled on camels.