2 Samuel 13:3-7

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

And he said to him, “Why are you, the king’s son, so depressed morning after morning? Will you not tell me?” So Amnon said to him, “I am in love with Tamar, the sister of my brother Absalom.”

Jonadab then said to him, “Lie down on your bed and pretend to be ill; when your father comes to see you, say to him, ‘Please have my sister Tamar come and give me food to eat, and have her prepare the food in my sight, so that I may see it and eat from her hand.’ ”

So Amnon lay down and pretended to be ill; when the king came to see him, Amnon said to the king, “Please have my sister Tamar come and make me a couple of pastries in my sight, so that I may eat from her hand.”

Then David sent a messenger to the house for Tamar, saying, “Go now to your brother Amnon’s house, and prepare food for him.”