2 Samuel 13:2-4

New Catholic Bible

² Amnon was obsessed with her to the point that he became ill because of his love for his sister Tamar, since she was a virgin and Amnon felt it was impossible for him even to approach her.

³ However, Amnon had a friend whose name was Jonadab. He was the son of David’s brother Shimeah, and he was an extremely devious man. ⁴ He asked Amnon: “O son of the king, why do you appear to be so depressed morning after morning? Will you not tell me?” Amnon replied: “I am in love with Tamar, the sister of my brother Absalom.”