1 Samuel 24 (KJV)

17 And he said to David, Thou art more righteous than I: for thou hast rewarded me good, whereas I have rewarded thee evil.

18 And thou hast shewed this day how that thou hast dealt well with me: forasmuch as when the Lord had delivered me into thine hand, thou killedst me not.

19 For if a man find his enemy, will he let him go well away? wherefore the Lord reward thee good for that thou hast done unto me this day.

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