1 Samuel 18:17

18:17 Then Saul said to David, “Here’s my oldest daughter, Merab. I want to give her to you in marriage. Only be a brave warrior for me and fight the battles of the Lord.” For Saul thought, “There’s no need for me to raise my hand against him. Let it be the hand of the Philistines!”

1 Samuel 18:2

18:2 Saul retained David on that day and did not allow him to return to his father’s house.

1 Samuel 17:8-11

17:8 Goliath stood and called to Israel’s troops, “Why do you come out to prepare for battle? Am I not the Philistine, and are you not the servants of Saul? Choose for yourselves a man so he may come down to me! 17:9 If he is able to fight with me and strike me down, we will become your servants. But if I prevail against him and strike him down, you will become our servants and will serve us.” 17:10 Then the Philistine said, “I defy Israel’s troops this day! Give me a man so we can fight each other!” 17:11 When Saul and all the Israelites heard these words of the Philistine, they were upset and very afraid.