2 Samuel 13:32

And Jonadab, the son of Shimeah David’s brother, answered and said, Let not my lord suppose that they have slain all the young men the king’s sons; for Amnon only is dead: for by the appointment of Absalom this hath been determined from the day that he forced his sister Tamar.

Cross-reference

2 Samuel 13:3–5 Historical context

In 2 Samuel 13:3-5, Jonadab advises Amnon on how to seduce Tamar—here he reveals he knew Absalom's motive, showing his inside knowledge.

In Genesis 27:41, Esau hates Jacob and plans to kill him—a parallel pattern of brotherly hatred leading to murder plot, like Absalom vs Amnon.