Joshua 21:39 lists two towns, Heshbon and Jazer, along with their surrounding lands, noting that these make up four cities in total. This verse is part of a record showing which towns were given to the Levites as their places to live within the territory of the other Israelite tribes.
The verse comes from a section where Joshua, as leader of Israel, is assigning towns to the Levite families as God commanded. Each town mentioned includes its "suburbs," meaning the pasturelands around the city, which were important for the Levites’ livestock and daily needs. The careful counting of "four cities in all" shows the attention to detail in dividing the land fairly among the Levites.