From 2 Samuel xviii, 1-17
The full text is here: Death of AbsalomThen said Joab, I may not tarry thus with thee. And he took three darts in his hand, and thrust them through the heart of Absalom, while he was yet alive in the midst of the oak. And ten young men that bare Joab's armor compassed about and smote Absalom, and slew him. And Joab blew the trumpet, and the people returned from pursuing after Israel: for Joab held back the people. And they took Absalom, and cast him into a great pit in the wood, and laid a very great heap of stones upon him: and all Israel fled every one to his tent.