1 Samuel 18:19

17Saul said to David, “Behold, my elder daughter Merab. I will give her to you as wife. Only be valiant for me, and fight the LORD’s battles.” For Saul said, “Don’t let my hand be on him, but let the hand of the Philistines be on him.”

18David said to 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?”

19But at the time when Merab, Saul’s daughter, should have been given to David, she was given to Adriel the Meholathite as wife.

20Michal, Saul’s daughter, loved David; and they told Saul, and the thing pleased him.

21Saul said, I will give her to him, that she may be a snare to him and that the hand of the Philistines may be against him. Therefore Saul said to David a second time, “You shall today be my son-in-law.”