2 Samuel 13:2-4

Living Bible

² Amnon became so tormented by his love for her that he became ill. He had no way of talking to her, for the girls and young men were kept strictly apart.^{[a] 3} But Amnon had a very crafty friend—his cousin Jonadab (the son of David’s brother Shimeah).

⁴ One day Jonadab said to Amnon, “What’s the trouble? Why should the son of a king look so haggard morning after morning?”

So Amnon told him, “I am in love with Tamar, my half sister.”