1 Samuel 29:2-4

29:2 When the leaders of the Philistines were passing in review at the head of their units of hundreds and thousands, David and his men were passing in review in the rear with Achish.

29:3 The leaders of the Philistines asked, “What about these Hebrews?” Achish said to the leaders of the Philistines, “Isn’t this David, the servant of King Saul of Israel, who has been with me for quite some time? I have found no fault with him from the day of his defection until the present time!”

29:4 But the leaders of the Philistines became angry with him and said to him, “Send the man back! Let him return to the place that you assigned him! Don’t let him go down with us into the battle, for he might become our adversary in the battle. What better way to please his lord than with the heads of these men?