Deuteronomy 19:2

Thou shalt separate three cities for thee in the midst of thy
land
From the cities they took possession of and dwelt in; and indeed from the cities of the Levites, which were given to them to inhabit; three were before ordered to be separated from those inhabited by the tribes of Reuben and Gad, and the half tribe of Manasseh, ( Deuteronomy 4:41-43 ) but these were to be in the midst of the land of Canaan; see ( Joshua 20:7 Joshua 20:8 ) ,

which the Lord thy God giveth thee to possess it:
which as it is often mentioned when this land is spoken of, so it carries in it a reason here why this order of the Lord's should be readily complied with, the whole land and all the cities of it being the gift of his to them.