1 Samuel 18:16-17
16 But all Israel and Judah loved David, because he led them in their campaigns.
17 Saul said to David, “Here is my older daughter Merab. I will give her to you in marriage; only serve me bravely and fight the battles of the Lord.” For Saul said to himself, “I will not raise a hand against him. Let the Philistines do that!”