The Philistines were gathered in Aphek in the hundreds and the thousands (possibly in the hundreds of thousands). Israel was camped at Jezreel. The Philistine commanders saw David in the back of the caravan with Achish. David and his men were supposed to be there, as they were Achish's personal detail. Verse 3 says: "The commanders of the Philistines said, “What are these Hebrews doing here?” And Achish said to the commanders of the Philistines, “Is this not David, the servant of Saul, king of Israel, who has been with me now for days and years, and since he deserted to me I have found no fault in him to this day.” The other commanders did not approve of David's presence and still viewed him as an enemy. Achish did not agree and vouched for David. Verse 6 says: "Then Achish called David, and said unto him, Surely, as the Lord liveth, thou hast been upright, and thy going out and thy coming in with me in the host is good in my sight: for I have not found evil in thee since the day of thy coming unto me unto this day: nevertheless the lords favour thee not." Even with Achish vouching for David the other commanders would not have any Hebrews in their midst. They suspected David of being a turncoat. They had good reason to as well. Look where David was. Considering where he was supposed to be, with Israel, he was already a turncoat. David's submission to the flesh continues. Where is the spirit and the Lord? He is not with David because David is with the flesh, not with the spirit.
David is unsure of why he must leave. Verse 8: "And David said unto Achish, But what have I done? and what hast thou found in thy servant so long as I have been with thee unto this day, that I may not go fight against the enemies of my lord the king?" David has gone so far and so deep into the flesh that even his people are his enemies. David's loyalty is evident. He serves well, but he serves man. David succumbed to the wishes and at first light, he and his men left and returned to the land of the Philistines.
David's service and sense of duty in this chapter is spectacular. It just faces the wrong master. Serve God in this manner and David would be free from the flesh. Even a heathen, Achish, has noticed how great of service David has given in verse 9 - "And Achish answered and said to David, I know that thou art good in my sight, as an angel of God: notwithstanding the princes of the Philistines have said, He shall not go up with us to the battle." If David serves like an angel, then we should as well. This is the only mention of God in this chapter and the heathen does it. Saul is lost and now he knows he lost in chapter 28. Now in chapter 29, David is also lost. Neither men have anything to fall back on. The flesh has left them with no duty and no purpose. Had they been with the spirit, all of this would be different. How would being with the spirit more change your life?