2 Samuel 13:3-5

3Amnon had a friend called Jonadab. He was the son of David's brother, Shimeah. Jonadab was a clever man.

4He said to Amnon, ‘You are the king's son! So why do you seem so sad every morning? Tell me about your trouble.’ Amnon said to him, ‘I love Tamar, my brother Absalom's sister.’

5Jonadab told him, ‘Go and lie down on your bed. Pretend that you are ill. Your father will come to see you. Then you can say to him, “Please send my sister Tamar in here to give me something to eat. I will watch her as she prepares the food. Then she can use her own hand to feed me.” ’