2 Samuel 18:9-18
Absalom happened to meet the servants of David. Absalom was riding on his mule, and the mule went under the thick branches of a great oak. His head caught fast in the oak, and he was left hanging between heaven and earth, while the mule that was under him went on. A man saw it, and told Joab, “I saw Absalom hanging in an oak.” Joab said to the man who told him, “What, you saw him! Why then did you not strike him there to the ground? I would have been glad to give you ten pieces of silver and a belt.”
But the man said to Joab, “Even if I felt in my hand the weight of a thousand pieces of silver, I would not raise my hand against the king's son; for in our hearing the king commanded you and Abishai and Ittai, saying: For my sake protect the young man Absalom! On the other hand, if I had dealt treacherously against his life (and there is nothing hidden from the king), then you yourself would have stood aloof.”
Joab said, “I will not waste time like this with you.” He took three spears in his hand, and thrust them into the heart of Absalom, while he was still alive in the oak. And ten young men, Joab's armor-bearers, surrounded Absalom and struck him, and killed him.
Then Joab sounded the trumpet, and the troops came back from pursuing Israel, for Joab restrained the troops. They took Absalom, threw him into a great pit in the forest, and raised over him a very great heap of stones. Meanwhile all the Israelites fled to their homes. Now Absalom in his lifetime had taken and set up for himself a pillar that is in the King's Valley, for he said, “I have no son to keep my name in remembrance”; he called the pillar by his own name. It is called Absalom's Monument to this day.