1 Samuel 27:1-2

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 escape into the land of the Philistines; and Saul will despair of me, to seek me any more in all the borders of Israel: so shall I escape out of his hand. And David arose, and passed over, he and the six hundred men that were with him, unto Achish the son of Maoch, king of Gath.