And David said in his heart, I shall now (a) 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.
(a) David distrusts God's protection and therefore flees to the idolaters, who were enemies to God's people.