The Gezrites were anciently seated in other places, Joshua 12:12, Joshua 16:3, but for some reasons not now known they changed their seats, as was then very usual, and seated themselves, and had for some considerable time lived, near the Amalekites. The Amalekites; the remnant of those whom Saul destroyed, 1Sa 15, who fled from his sword, and retired into remote and desert places.
Related Commentaries of 1 Samuel 27:8
1 Samuel 27:8
8 And David and his men went up, and invaded the Geshurites, and the Gezrites,c and the Amalekites: for those nations were of old the inhabitants of the land, as thou goest to Shur, even unto the land of Egypt.