1 Samuel 24:20-22

Darby Translation

²⁰ And now behold, I know that thou shalt certainly be king, and that the kingdom of Israel shall be established in thy hand.

²¹ Swear now therefore to me by Jehovah, that thou wilt not cut off my seed after me, and that thou wilt not destroy my name out of my father's house.

²² And David swore to Saul. And Saul went home; and David and his men went up to the stronghold.