1 Samuel 27:9-11

9And David smote the land, and left neither man nor woman alive, and took away the sheep, and the oxen, and the asses, and the camels, and the apparel, and returned, and came to Achish.

10So Achish said, Have ye not made a raid to-day? And David said, Against the south of Judah, and against the south of the Jerahmeelites, and against the south of the Kenites.

11And David left neither man nor woman alive, to bring [them] to Gath, for he said, Lest they should tell of us, saying, So did David. And such was his custom as long as he abode in the country of the Philistines.