C. F. Keil and Franz Delitzsch on 1 Samuel 24:20-21

1Sa 24:20-21

This wish was expressed in perfect sincerity. David’s behaviour towards him had conquered for the moment the evil demon of his heart, and completely altered his feelings. In this better state of mind he felt impelled even to give utterance to these words, “I know that thou wilt be king, and the sovereignty will have perpetuity in thy hand.” Saul could not prevent this conviction from forcing itself upon him, after his own rejection and the failure of all that he attempted against David; and it was this which drove him to persecute David whenever the evil spirit had the upper hand in his soul. But now that better feelings had arisen in his mind, he uttered it without envy, and merely asked David to promise on oath that he would not cut off his descendants after his death, and seek to exterminate his name from his father’s house. A name is exterminated when the whole of the descendants are destroyed, - a thing of frequent occurrence in the East in connection with a change of dynasties, and one which occurred again and again even in the kingdom of the ten tribes (vid., 1Ki 15:28., 1Sa 16:11.; 2 Kings 10).