I Samuel Chapter 27

27:1
And David said in his heart, I shall now perish one day by the hand of Saul: there is nothing better for me than that I should speedily escape into the land of the Philistines; and Saul shall despair of me, to seek me any more in any coast of Israel: so shall I escape out of his hand.

27:4
And it was told Saul that David was fled to Gath: and he sought no more again for him.

27:8
And David and his men went up, and invaded the Geshurites, and the Gezrites, and the Amalekites: for those nations were of old the inhabitants of the land, as thou goest to Shur, even unto the land of Egypt.

27:10-12
And Achish said, Whither have ye made a road today? And David said, Against the south of Judah, and against the south of the Jerahmeelite, and against the south of the Kenites.
And David saved neither man nor woman alive, to bring tidings to Gath, saying, Lest thy should tell on us, saying, So did David, and so will be his manner all the while he dwelleth 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.