All the cities of the Gershonites according to their families were thirteen cities with their common-lands.
Joshua 21:33
Surrounding context
21:32 and from the tribe of Naphtali, Kedesh in Galilee with its common-land (a city of refuge for the slayer), Hammoth Dor with its common-land, and Kartan with its common-land: three cities.
21:33 All the cities of the Gershonites according to their families were thirteen cities with their common-lands.
21:34 And to the families of the children of Merari, the rest of the Levites, from the tribe of Zebulun, Jokneam with its common-land, Kartah with its common-land,