1 Samuel 18:17-18

17Then Saul said to David, “Here is my older daughter Merab. I will give her to you in marriage. Only be valiant for me and fight the LORD’s battles.” But Saul was thinking, “I need not raise my hand against him; let the hand of the Philistines be against him.”

18And David said to Saul, “Who am I, and what is my family or my father’s clan in Israel, that I should become the son-in-law of the king?”