Swear now ... - The same request which Jonathan made 1 Samuel 20:15. The deep, genealogical feeling of the Israelites breaks out here as so often elsewhere.
Related Commentaries of 1 Samuel 24:21
1 Samuel 24:21
21 Swear now therefore unto me by the LORD, that thou wilt not cut off my seed after me, and that thou wilt not destroy my name out of my father's house.