2 Samuel 18:5-7

And the king gave this command to Joab, Abishai, and Ittai: “For my sake, deal gently with young Absalom.” And all the troops heard the king give this order to his commanders. So the battle began in the forest of Ephraim, and the Israelite troops were beaten back by David’s men. There was a great slaughter that day, and 20,000 men laid down their lives.