1 Samuel.
Chapter 29.
Now the Philistines brought all their forces together at Aphek, while Israel camped by the spring in Jezreel. 
As the Philistine leaders marched out with their units of hundreds and thousands, David and his men marched behind them with Achish. 
Then the commanders of the Philistines asked, “What about these Hebrews?” Achish replied, “Is this not David, the servant of King Saul of Israel? He has been with me all these days, even years, and from the day he defected until today I have found no fault in him.” 
But the commanders of the Philistines were angry with Achish and told him, “Send that man back and let him return to the place you assigned him. He must not go down with us into battle only to become our adversary during the war. What better way for him to regain the favor of his master than with the heads of our men? 
Is this not the David about whom they sing in their dances: ‘Saul has slain his thousands, and David his tens of thousands’?” 
So Achish summoned David and told him, “As surely as the LORD lives, you have been upright, and it seems right in my sight that you should march in and out with me in the army, because I have found no fault in you from the day you came to me until this day. But you are not good in the sight of the leaders. 
Therefore turn back now and go in peace, so that you will not do anything to displease the leaders of the Philistines.” 
“But what have I done?” David replied. “What have you found against your servant, from the day I came to you until today, to keep me from going along to fight against the enemies of my lord the king?” 
Achish replied, “I know that you are as pleasing in my sight as an angel of God. But the commanders of the Philistines have said, ‘He must not go into battle with us.’ 
Now then, get up early in the morning, along with your master’s servants who came with you, and go as soon as it is light.” 
So David and his men got up early in the morning to return to the land of the Philistines. And the Philistines went up to Jezreel. 
