2 Samuel 13:3-6

3But Amnon had a friend, whose name was Jonadab, the son of Shimeah David’s brother: and Jonadab was a very subtil man.

4And he said to him, Why art thou, being the king’s son, pining from day to day? wilt thou not tell me? And Amnon said to him, I love Tamar, my brother Absalom’s sister.12

5And Jonadab said to him, Lay thee down on thy bed, and pretend that thou art sick: and when thy father cometh to see thee, say to him, I pray thee, let my sister Tamar come, and give me food, and prepare the food in my sight, that I may see it, and eat it at her hand.

6So Amnon lay down, and pretended that he was sick: and when the king came to see him, Amnon said to the king, I pray thee, let Tamar my sister come, and make for me a couple of cakes in my sight, that I may eat at her hand.