1 Samuel 24:16-22 NIV

[16] When David finished saying this, Saul asked, “Is that your voice, David my son?” And he wept aloud. [17] “You are more righteous than I,” he said. “You have treated me well, but I have treated you badly. [18] You have just now told me about the good you did to me; the LORD delivered me into your hands, but you did not kill me. [19] When a man finds his enemy, does he let him get away unharmed? May the LORD reward you well for the way you treated me today. [20] I know that you will surely be king and that the kingdom of Israel will be established in your hands. [21] Now swear to me by the LORD that you will not kill off my descendants or wipe out my name from my father’s family.” [22] So David gave his oath to Saul. Then Saul returned home, but David and his men went up to the stronghold.