Parallel
2 Samuel 13:2
King James Version (1769 Blayney revision, with Apocrypha) · Berean Standard Bible
And Amnon was so vexed, that he fell sick for his sister Tamar; for she was a virgin; and Amnon thought it hard (note: Heb. it was marvellous or hidden in the eyes of Amnon) for him to do any thing to her.
Amnon was sick with frustration over his sister Tamar, for she was a virgin, and it seemed implausible for him to do anything to her.