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.
"Secondly, Achish realized that as soon as David did attack his own people, he would lose for ever the possibility of changing sides." [Note: David Payne, p. 140.] 