28 Then Ab'salom commanded his servants, "Mark when Amnon's heart is merry with wine, and when I say to you, 'Strike Amnon,' then kill him. Fear not; have I not commanded you? Be courageous and be valiant." 29 So the servants of Ab'salom did to Amnon as Ab'salom had commanded. Then all the king's sons arose, and each mounted his mule and fled.
30 While they were on the way, tidings came to David, "Ab'salom has slain all the king's sons, and not one of them is left." 31 Then the king arose, and rent his garments, and lay on the earth; and all his servants who were standing by rent their garments. 32 But Jon'adab the son of Shim'e-ah, David's brother, said, "Let not my lord suppose that they have killed all the young men the king's sons, for Amnon alone is dead, for by the command of Ab'salom this has been determined from the day he forced his sister Tamar. 33 Now therefore let not my lord the king so take it to heart as to suppose that all the king's sons are dead; for Amnon alone is dead." 34 But Ab'salom fled. And the young man who kept the watch lifted up his eyes, and looked, and behold, many people were coming from the Horona'im road by the side of the mountain. 35 And Jon'adab said to the king, "Behold, the king's sons have come; as your servant said, so it has come about." 36 And as soon as he had finished speaking, behold, the king's sons came, and lifted up their voice and wept; and the king also and all his servants wept very bitterly.
Matthew Henry's Commentary on 2 Samuel 13:28-36
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.