1 Samuel 27:10-12

10When Achish would ask, “Where did you raid today?” David would say, “The Negev of Judah” or “The Negev of Jeharmeel” or “The Negev of the Kenites.”

11Neither man nor woman would David leave alive so as to bring them back to Gath. He was thinking, “This way they can’t tell on us, saying, ‘This is what David did.’” Such was his practice the entire time that he lived in the country of the Philistines.

12So Achish trusted David, thinking to himself, “He is really hated among his own people in Israel! From now on he will be my servant.”