2 Samuel 13:2-4

American Standard Version

² And Amnon was so vexed that he fell sick because of his sister Tamar; for she was a virgin; and it seemed hard to Amnon to do anything unto her. ³ But Amnon had a friend, whose name was Jonadab, the son of Shimeah, David’s brother: and Jonadab was a very subtle man. ⁴ And he said unto him, Why, O son of the king, art thou thus lean ^[a]from day to day? wilt thou not tell me? And Amnon said unto him, I love Tamar, my brother Absalom’s sister.