1 Samuel 27:9-11

9Whenever David attacked the territory, he left no man or woman alive. He also took sheep, cattle, donkeys, camels, and clothing and returned to Achish.

10Achish would ask, “Whom did you raid today?” And David would answer, “the Negev in Judah,” or “the portion of the Negev where the descendants of Jerahmeel live,” or “the portion of the Negev where the Kenites live.”

11He did not bring a single man or woman back to Gath alive. He thought, “They could tell Achish what I ⌞really⌟ did.” This was his practice as long as he lived in Philistine territory.