Swear to me therefore by the LORD that you will not cut off my offspring after me, and that you will not destroy my name out of my father’s house.”
Here we have, I. Saul's penitent reply to David's speech. It was strange that he had patience to hear him out, considering how outrageous he was against him, and how cutting David's discourse was. But God restrained him and his men; and we may suppose Saul struck with amazement at the singularity of the event, and much more when he found how much he had lain at David's mercy.
Commenting on 1 Samuel 24:16-22
Swear now therefore unto me by the Lord,.... By the Word of the Lord, as the, Targum: that thou wilt not cut off my seed after me; as was usually done in despotic governments in the eastern countries, and is at this day, when one is advanced to the throne of another, by whom issue is left, who may be rivals and competitors with him...
Swear now - Saul knew that an oath would bind David, though it was insufficient to bind himself; see Sa1 19:6. He had sworn to his son Jonathan that David should not be slain; and yet sought by all means in his power to destroy him!