2 Samuel 13:28-30

28Absalom told his men, “Wait until Amnon gets drunk; then at my signal, kill him! Don’t be afraid. I’m the one who has given the command. Take courage and do it!”

29So at Absalom’s signal they murdered Amnon. Then the other sons of the king jumped on their mules and fled.

30As they were on the way back to Jerusalem, this report reached David: “Absalom has killed all the king’s sons; not one is left alive!”