1 Samuel 18:15-17 New King James Version (NKJV)

15. Therefore, when Saul saw that he behaved very wisely, he was afraid of him.

16. But all Israel and Judah loved David, because he went out and came in before them.

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

1 Samuel 18