1 Samuel 24:17-21

17and said to David, “You are more righteous than I, for you have done what is good to me though I have done what is evil to you.

18You yourself have told me today what good you did for me: when the Lord handed me over to you, you didn’t kill me.

19When a man finds his enemy, does he let him go unharmed? May the Lord repay you with good for what you’ve done for me today.

20“Now I know for certain you will be king, and the kingdom of Israel will be established in your hand.

21Therefore swear to me by the Lord that you will not cut off my descendants or wipe out my name from my father’s family.”