1 Samuel 18:17-19

18:17 Then Saul said to David, “Here’s my oldest daughter, Merab. I want to give her to you in marriage. Only be a brave warrior for me and fight the battles of the Lord.” For Saul thought, “There’s no need for me to raise my hand against him. Let it be the hand of the Philistines!”

18:18 David said to Saul, “Who am I? Who are my relatives or the clan of my father in Israel that I should become the king’s son-in-law?” 18:19 When the time came for Merab, Saul’s daughter, to be given to David, she instead was given in marriage to Adriel, who was from Meholah.

1 Samuel 18:21

18:21 Saul said, “I will give her to him so that she may become a snare to him and the hand of the Philistines may be against him.” So Saul said to David, “Today is the second time for you to become my son-in-law.”