2 Samuel 13:15-17

Then Amnon hated her exceedingly— The flux and reflux of passion in a brutal breast are here finely painted. Commentators are at a loss to account for this sudden and excessive hatred; and, indeed, there seems to be something extraordinary in it. Tamar's rape had an effect upon her ravisher directly contrary to that of Dinah upon her's. But their circumstances were different. Hope seconded and supported Shechem's passion, but despair drove Amnon's into its opposite extreme. This is often observed to be the case with passions too tumultuous and unruly. Amnon's mind was first agitated by lust, and then by remorse, which drove to different extremes like the vibrations of a pendulum. God abandoned him thus to the tumult of his own intemperate mind, to make this other punishment of David's adultery more flagrant, and the prophet's prediction of raising up evil to him out of his own house more conspicuous; for Amnon's barbarous behaviour now precluded all possibility of concealing his guilt.