5 Then the king ordered Joab and Abishai and Ittai, "Deal gently for my sake with the young man Absalom." The whole army heard what the king commanded the three captains regarding Absalom. 6 The army took the field to meet Israel. It turned out that the battle was joined in the Forest of Ephraim. 7 The army of Israel was beaten badly there that day by David's men, a terrific slaughter - twenty thousand men! 8 There was fighting helter-skelter all over the place - the forest claimed more lives that day than the sword!
9 Absalom ran into David's men, but was out in front of them riding his mule, when the mule ran under the branches of a huge oak tree. Absalom's head was caught in the oak and he was left dangling between heaven and earth, the mule running right out from under him. 10 A solitary soldier saw him and reported it to Joab, "I just saw Absalom hanging from an oak tree!" 11 Joab said to the man who told him, "If you saw him, why didn't you kill him then and there? I'd have rewarded you with ten pieces of silver and a fancy belt." 12 The man told Joab, "Even if I'd had a chance at a thousand pieces of silver, I wouldn't have laid a hand on the king's son. We all heard the king command you and Abishai and Ittai, 'For my sake, protect the young man Absalom.' 13 Why, I'd be risking my life, for nothing is hidden from the king. And you would have just stood there!" 14 Joab said, "I can't waste my time with you." He then grabbed three knives and stabbed Absalom in the heart while he was still alive in the tree; 15 by then Absalom was surrounded by ten of Joab's armor bearers; they hacked away at him and killed him.
Matthew Henry's Commentary on 2 Samuel 18:5-15
Commentary on 2 Samuel 18:1-8
(Read 2 Samuel 18:1-8)
How does David render good for evil! Absalom would have only David smitten; David would have only Absalom spared. This seems to be a resemblance of man's wickedness towards God, and God's mercy to man, of which it is hard to say which is most amazing. Now the Israelites see what it is to take counsel against the Lord and his anointed.
Commentary on 2 Samuel 18:9-18
(Read 2 Samuel 18:9-18)
Let young people look upon Absalom, hanging on a tree, accursed, forsaken of heaven and earth; there let them read the Lord's abhorrence of rebellion against parents. Nothing can preserve men from misery and contempt, but heavenly wisdom and the grace of God.