The lords or commanders of the Philistine city-states mustered their troops and marched north to the town of Aphek. It is interesting that the first place the Philistines mustered their troops for battle against the Israelites in this book was at Aphek ( 1 Samuel 4:1), and the last place they did so that the writer recorded was also at Aphek. This indicates that Israel had not subdued her neighbor enemy effectively during Saul"s reign because of his failure as her leader. Aphek stood near Philistia"s northern border with Israel. The Philistine commanders were on their way to the Jezreel Valley to battle King Saul. Jezreel was a town on the northwestern slope of Mt. Gilboa about three miles south of Shunem (cf. 1 Samuel 28:4). David and his600 mercenaries were bringing up the rear in the Philistine procession. The Philistine commanders noticed David and his men and asked each other why Hebrew soldiers were accompanying them since they were going to war against the Israelites. "Hebrew" is the common word that non-Israelites used to describe the Israelites, according to the Old Testament writers. It was an ethnic designation. Achish, whom David had deceived into thinking that he was no longer loyal to Saul, came to his defense. David had lived in Philistia now for almost16 months (cf. 1 Samuel 27:7). The other Philistine kings could hardly believe how naive Achish was being. They saw that David would probably turn against them in the upcoming battle to regain acceptance with his commander, Saul. They proceeded to use the same phrase Achish had used to defend David, "Is this not David?" to impress on their gullible comrade what a danger David posed to them. David had not only slain many of Israel"s enemies, including many Philistines, but he also enjoyed solidarity with Saul in the minds of all the people, which the song they quoted assumed. [source][source][source]