5 And the king gave this command to Joab, Abishai, and Ittai: "For my sake, deal gently with young Absalom." And all the troops heard the king give this order to his commanders. 6 So the battle began in the forest of Ephraim, 7 and the Israelite troops were beaten back by David's men. There was a great slaughter that day, and 20,000 men laid down their lives. 8 The battle raged all across the countryside, and more men died because of the forest than were killed by the sword.
9 During the battle, Absalom happened to come upon some of David's men. He tried to escape on his mule, but as he rode beneath the thick branches of a great tree, his hair got caught in the tree. His mule kept going and left him dangling in the air. 10 One of David's men saw what had happened and told Joab, "I saw Absalom dangling from a great tree." 11 "What?" Joab demanded. "You saw him there and didn't kill him? I would have rewarded you with ten pieces of silver and a hero's belt!" 12 "I would not kill the king's son for even a thousand pieces of silver, " the man replied to Joab. "We all heard the king say to you and Abishai and Ittai, 'For my sake, please spare young Absalom.' 13 And if I had betrayed the king by killing his son-and the king would certainly find out who did it-you yourself would be the first to abandon me." 14 "Enough of this nonsense," Joab said. Then he took three daggers and plunged them into Absalom's heart as he dangled, still alive, in the great tree. 15 Ten of Joab's young armor bearers then surrounded Absalom 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.