1 Samuel 27:1-2

But David thought to himself, “One of these days I will be destroyed by the hand of Saul. The best thing I can do is to escape to the land of the Philistines. Then Saul will give up searching for me anywhere in Israel, and I will slip out of his hand.” So David and the six hundred men with him left and went over to Achish son of Maok king of Gath.