2 Samuel 18:5-9

But the king commanded Joab, Abishai, and Ittai, saying, “Deal gently with the young man Absalom for my sake.” And all the people heard when the king commanded all the commanders regarding Absalom.

Then the people went out to the field against Israel, and the battle took place in the forest of Ephraim.

The people of Israel were defeated there by the servants of David, and the slaughter there that day was great, twenty thousand men.

For the battle there was spread over the whole countryside, and the forest devoured more people that day than the sword devoured.

Now Absalom encountered the servants of David. Absalom was riding on his mule, and the mule went under the branches of a massive oak. Then his head caught firmly in the oak, and he was left hanging between the sky and earth, while the mule that was under him kept going.