2 Amnon was so tormented that he made himself ill because of his sister Tamar, for she was a virgin and it seemed impossible to Amnon to do anything to her.

Matthew Henry's Commentary on 2 Samuel 13:2

Commentary on 2 Samuel 13:1-20

(Read 2 Samuel 13:1-20)

From henceforward David was followed with one trouble after another. Adultery and murder were David's sins, the like sins among his children were the beginnings of his punishment: he was too indulgent to his children. Thus David might trace the sins of his children to his own misconduct, which must have made the anguish of the chastisement worse. Let no one ever expect good treatment from those who are capable of attempting their seduction; but it is better to suffer the greatest wrong than to commit the least sin.