24 Then Absalom came to the king and said, "Kindly note, your servant has sheepshearers; please, let the king and his servants go with your servant." 25 But the king said to Absalom, "No, my son, let us not all go now, lest we be a burden to you." Then he urged him, but he would not go; and he blessed him. 26 Then Absalom said, "If not, please let my brother Amnon go with us." And the king said to him, "Why should he go with you?" 27 But Absalom urged him; so he let Amnon and all the king's sons go with him. 28 Now Absalom had commanded his servants, saying, "Watch now, when Amnon's heart is merry with wine, and when I say to you, 'Strike Amnon!' then kill him. Do not be afraid. Have I not commanded you? Be courageous and valiant." 29 So the servants of Absalom did to Amnon as Absalom had commanded. Then all the king's sons arose, and each one got on his mule and fled.
30 And it came to pass, while they were on the way, that news came to David, saying, "Absalom has killed all the king's sons, and not one of them is left!"
Matthew Henry's Commentary on 2 Samuel 13:24-30
Commentary on 2 Samuel 13:21-29
(Read 2 Samuel 13:21-29)
Observe the aggravations of Absalom's sin: he would have Ammon slain, when least fit to go out of the world. He engaged his servants in the guilt. Those servants are ill-taught who obey wicked masters, against God's commands. Indulged children always prove crosses to godly parents, whose foolish love leads them to neglect their duty to God.
Commentary on 2 Samuel 13:30-39
(Read 2 Samuel 13:30-39)
Jonadab was as guilty of Ammon's death, as of his sin; such false friends do they prove, who counsel us to do wickedly. Instead of loathing Absalom as a murderer, David, after a time, longed to go forth to him. This was David's infirmity: God saw something in his heart that made a difference, else we should have thought that he, as much as Eli, honoured his sons more than God.