1 Samuel 18:16 (KJV)

And Saul cast the javelin; for he said, I will smite David even to the wall with it. And David avoided out of his presence twice.

And Saul was afraid of David, because the LORD was with him, and was departed from Saul.

Therefore Saul removed him from him, and made him his captain over a thousand; and he went out and came in before the people.

And David behaved himself wisely in all his ways; and the LORD was with him.

Wherefore when Saul saw that he behaved himself very wisely, he was afraid of him.

And Saul said to David, Behold my elder daughter Merab, her will I give thee to wife: only be thou valiant for me, and fight the LORD's battles. For Saul said, Let not mine hand be upon him, but let the hand of the Philistines be upon him.

And David said unto 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?

But it came to pass at the time when Merab Saul's daughter should have been given to David, that she was given unto Adriel the Meholathite to wife.

And Michal Saul's daughter loved David: and they told Saul, and the thing pleased him.

And Saul said, I will give him her, that she may be a snare to him, and that the hand of the Philistines may be against him. Wherefore Saul said to David, Thou shalt this day be my son in law in the one of the twain.