1 Samuel 18:27-29

Wherefore David arose and went, he and his men, and slew of the Philistines two hundred men; and David brought their foreskins, and they gave them in full tale to the king, that he might be the king's son in law. And Saul gave him Michal his daughter to wife.

And Saul saw and knew that the LORD was with David, and that Michal Saul's daughter loved him.

And Saul was yet the more afraid of David; and Saul became David's enemy continually.