John Calvin Commentary Joshua 21:41

"All the cities of the Levites in the midst of the possession of the children of Israel were forty and eight cities with their suburbs." — Joshua 21:41 (ASV)

All the cities of the Levites, etc. This passage especially shows what I have already referred to more than once: that the boundaries of the other tribes were not so limited as to prevent them from encompassing a far larger number of cities than are actually mentioned. It is perfectly well known that Levi was the least numerous of all the tribes.

How, then, could it have been equitable for Levi to be allowed to expand over four times the space allotted to the tribe of Zebulun, which, though more populous, is mentioned as possessing only twelve cities? Only sixteen are enumerated as belonging to the tribe of Issachar, nineteen to the tribe of Naphtali, and twenty-two to the tribe of Asher. It would surely have been an unequal division to give the greater number of cities for habitation to the smaller population. Therefore, we infer that not only were the villages listed here as associated with the cities suitable for living in, but also that other unmentioned cities were included. In short, the extent of Levi's allotment makes it perfectly obvious how large and ample the territories of the other tribes must have been.