2 Samuel 13:1-6

1 Now after this, it came about that Absalom, David's son, had a beautiful sister, whose name was Tamar; and David's son Amnon was in love with her.
2 And he was so deeply in love that he became ill because of his sister Tamar; for she was a virgin, and so it seemed hard to Amnon to do anything to her.
3 But Amnon had a friend whose name was Jonadab, the son of Shimeah, David's brother: and Jonadab was a very wise man.
4 And he said to him, O son of the king, why are you getting thinner day by day? will you not say what your trouble is? And Amnon said to him, I am in love with Tamar, my brother Absalom's sister.
5 Then Jonadab said to him, Go to your bed, and let it seem that you are ill: and when your father comes to see you, say to him, Let my sister Tamar come and give me bread, and get the food ready before my eyes, so that I may see it and take it from her hand.
6 So Amnon went to bed and made himself seem ill: and when the king came to see him, Amnon said to the king, Please let my sister Tamar come and make me one or two cakes before my eyes, so that I may take food from her hand.