2 Samuel 18:6-8

18:6 Then the army marched out to the field to fight against Israel. The battle took place in the forest of Ephraim. 18:7 The army of Israel was defeated there by David’s men. The slaughter there was great that day – 20,000 soldiers were killed. 18:8 The battle there was spread out over the whole area, and the forest consumed more soldiers than the sword devoured that day.