1 Samuel 27:9-11

9And David would strike the land and would leave neither man nor woman alive, but would take away the sheep, the oxen, the donkeys, the camels, and the garments, and come back to Achish. 10When Achish asked, “Where have you made a raid today?” David would say, “Against the Negeb of Judah,” or, “Against the Negeb of the Jerahmeelites,” or, “Against the Negeb of the Kenites.” 11And David would leave neither man nor woman alive to bring news to Gath, thinking, “lest they should tell about us and say, ‘So David has done.’” Such was his custom all the while he lived in the country of the Philistines.