2 Samuel 18:2, 14-15

David sent out his troops, a third under the command of Joab, a third under Joab’s brother Abishai son of Zeruiah, and a third under Ittai the Gittite. The king told the troops, “I myself will surely march out with you.”

Joab said, “I’m not going to wait like this for you.” So he took three javelins in his hand and plunged them into Absalom’s heart while Absalom was still alive in the oak tree. And ten of Joab’s armor-bearers surrounded Absalom, struck him and killed him.