The Septuagint adds a helpful explanation: but he did not vex the spirit of Amnon his son, because he loved him, because he was his first-born.…

He was very angry. —The Septuagint adds, “but he vexed not the spirit of Amnon his son, because he loved him, because he was h…

But when King David heard of all these things
Of Amnon's ravishing Tamar, and turning her out of doors in that inhum…

Observe the aggravations of Absalom's sin: he had Ammon killed when he was least fit to die. He involved his servants in the guilt.