2 Samuel 5:17-19

When the Philistines heard that David had been made king over Israel, all the Philistines went to look for him. But when David heard the news, he went down to the stronghold. The Philistines came and camped in the Valley of Rephaim. David asked the LORD, “Should I attack the Philistines? Will you hand them over to me?” The LORD said to David, “Go! I will certainly hand them over to you.”