Achish said to David, "You must understand that you and your men will accompany me in the army."I'm sure David was either anxious or praying real hard or both.David said, "Then you will see for yourself what your servant can do."
1 Samuel 27.1-2
The commanders of the Philistines asked, "What about these Hebrews? .... Send the man back, that he may return to the plaace you assigned him. He must not go with us into battle, or he will turn against us during the fighting. How better could he regain his master's favor than by taking the heads of our own men? Isn't this the David they sang about in their dances:Whew! So he didn't have to fight against his own people. The text doesn't say so, but I am sure that God's hand was in this.'Saul has slain his thousands,
and David his tens of thousands'?"from 1 Samuel 29.2-5