1 Samuel 27:8-12

And David and his men went up, and made a raid upon the Geshurites, and the Girzites, and the Amalekites; for those nations were the inhabitants of the land, who were of old, as thou goest to Shur, even unto the land of Egypt. And David smote the land, and saved neither man nor woman alive, and took away the sheep, and the oxen, and the asses, and the camels, and the apparel; and he returned, and came to Achish. And Achish said, Against whom have ye 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. And David saved neither man nor woman alive, to bring them to Gath, saying, Lest they should tell of us, saying, So did David, and so hath been his manner all the while he hath dwelt in the country of the Philistines. And Achish believed David, saying, He hath made his people Israel utterly to abhor him; therefore he shall be my servant for ever.