1 Samuel 18:17-21

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 what is my life or my father’s family in Israel, that I should be the king’s son-in-law?” 19So it came about at the time when Merab, Saul’s daughter, should have been given to David, that she was given to 5Adriel 6the Meholathite for a wife.

20Now 7Michal, Saul’s daughter, loved David. When they told Saul, the thing was agreeable 8to him. 21Saul thought, “I will give her to him that she may become a snare to him, and 9that the hand of the Philistines may be against him.” Therefore Saul said to David, “10For a second time you may be my son-in-law today.”