2 Samuel 18:8 (KJV)

So the people went out into the field against Israel: and the battle was in the wood of Ephraim;

Where the people of Israel were slain before the servants of David, and there was there a great slaughter that day of twenty thousand men.

For the battle was there scattered over the face of all the country: and the wood devoured more people that day than the sword devoured.

And Absalom met the servants of David. And Absalom rode upon a mule, and the mule went under the thick boughs of a great oak, and his head caught hold of the oak, and he was taken up between the heaven and the earth; and the mule that was under him went away.

And a certain man saw it, and told Joab, and said, Behold, I saw Absalom hanged in an oak.