2 Samuel 13:36

The king also and all his servants wept very sore. The narrative sets very clearly before us the great terror of the king, who at first supposes that all his sons are murdered; there is then suspense while Jonadab suggests that one only has been sacrificed to private vengeance; then quickly comes the watchman's report of the appearance of much people rapidly descending the hillside, and this is followed by the hasty rush of the fugitives into his presence, and the terrible certainty that one son has, with long premeditated malice, murdered his brother. And as he wept, David, we may feel sure, thought of Uriah, murdered because of his own base passions, whereas Amnon had brought death upon himself by following, alas! the example of his own father. He would think, too, of the words of his sentence, that "the sword should never depart from his house." It had claimed one victim, and who could now stop the outburst of angry passions in a family which previously had dwelt in kindly friendship? Probably, too, he reproached himself for not punishing Amnon. Had he done so with sufficient severity to have satisfied Absalom, he would have saved the life of his firstborn, and not have driven his second son into terrible crime. He had not done so because his own sins had tied his hands. Yes; David had good reason for weeping sore.