2 Samuel 13:3-5

3Amnon had a friend by the name of Jonadab, a son of David’s brother Shimea. Jonadab was a very clever man.

4He asked Amnon, “Why are you, the king’s son, so worn out morning after morning? Won’t you tell me?” “I’m in love with Absalom’s sister Tamar,” he answered.

5Then Jonadab told him, “Lie down on your bed. Act sick, and when your father comes to see you, say to him, ‘Please let my sister Tamar come to feed me. She can prepare a meal in front of me as I watch her, and she can feed me.’ ”