1 Samuel 18:17-18

17Then Saul said to David, “1Here is my older daughter Merab; I will give her to you as a wife, only be a valiant man for me and fight 2the Lord’s battles.” For Saul thought, “My hand shall not be against him, but 3let the hand of the Philistines be against him.”

18But David said to Saul, “4Who am I, and who is my family, or my father’s family in Israel, that I should be the king’s son-in-law?”