Jamieson, Fausset and Brown on Joshua 13:2-7

2-6. This is the land that yet remaineth--that is, to be acquired. This section forms a parenthesis, in which the historian briefly notices the districts yet unsubdued; namely, first, the whole country of the Philistines--a narrow tract stretching about sixty miles along the Mediterranean coast, and that of the Geshurites to the south of it (1Sa 27:8). Both included that portion of the country "from Sihor, which is before Egypt," a small brook near El-Arish, which on the east was the southern boundary of Canaan, to Ekron, the most northerly of the five chief lordships or principalities of the Philistines.