New Defender's Study Bible Notes
27:3 with Achish at Gath. David had previously spent a short time with Achish at Gath, feigning insanity (I Samuel 21:10-15). This time, however, Achish welcomed him and his six hundred strong fighting men, assuming he would help the Philistines in future conflicts with Saul.
27:6 Ziklag. The city of Ziklag was in Judah’s territory; far to the south, but still controlled by pagan tribes. By destroying these cities and their inhabitants, David was both fulfilling God’s command to Joshua, but also ingratiating himself with Achish.