After several years of running from King Saul through the land of Judah David realized that there must be an easier and safer way to wait for the Lord’s plan to develop in his life. In addition to this the David and his men realized they could not continue to stay on the run with their families. They needed to find a place to settle down. David went into the Philistine kingdom to the city of Gath which was ruled by King Achish Ben-Maoch. Along with David and has immediate family came his 600 men and their families. They would live among the Philistines for the next 16 months.
David and his men basically followed a practice very well documented in the Near East of offering their services as mercenaries, or professional military personal, in exchange for land. It appears that the land that David and his men were rewarded with was actually a town. King Achish Ben-Maoch gave David and his 600 men the town of Ziklag, which the text says “has belonged to the kings of Judah ever since.” This editorial note helps support a very early date for the writing of 1 Samuel since this statement would only be true up through the beginning of Rehoboam's (Solomon's son) reign, because Egyptian king Shishaq took control of this area in his well documented campaign in 925 BC (1 Kings 14:25). Although Hezekiah controlled this area around 740-710 BC, the territory that included Ziklag was soon controlled by Assyrians in the 600's. The only time this statement would have been true and made sense would have been the earliest years of Rehoboam's reign (930-925 BC).
David’s defection to the Philistines is understood in the Philistine’s perspective as David’s reaction to Saul’s unjust and oppressive behavior towards David and the other men who appear to have already been fugitives from Saul’s government when they joined up with David in the Judean wilderness.
This practice of using mercenaries was common and was, in fact, used by David when he hired Cretans and Philistines to serve as his personal body guard (they are called Kerethites and Pelethites or 2 Samuel 8:18; 23:22-23). These mercenaries would be more dependable for a king than native soldiers or citizen soldiers since mercenaries only reward would have come from the king and his rewarding of these troops from the bounty of the king’s success. Political interest or national factions will be less likely to influence a professional mercenary.
Ziklag was a good location for David to operate from since it was 35-40 miles south of Gath in the land of Philistia which was far enough away to avoid continual Philistine supervision. Ziklag was also a safe distance from King Saul.