1 Samuel 18:17-18

And Saul said to David, Behold my elder daughter Merab, her will I give thee to wife: only be thou valiant for me, and fight the LORD's battles. For Saul said, Let not mine hand be upon him, but let the hand of the Philistines be upon him. And David said unto Saul, Who am I? and what is my life, or my father's family in Israel, that I should be son in law to the king?