Matthew Henry on Numbers 35:1-8

The cities of the priests and Levites were not only to accommodate them, but to place them, as religious teachers, in several parts of the land. For though the typical service of the tabernacle or temple was only in one place, the preaching of the word of God, and prayer and praise, were not thus confined. These cities were to be given out of each tribe. Each thus made a grateful acknowledgement to God. Each tribe had the benefit of the Levites dwelling amongst them, to teach them the knowledge of the Lord; thus no parts of the country were left to sit in darkness. The gospel provides that he who is taught in the word, should communicate to him that teaches, in all good things, Ga 6:6. We are to free God's ministers from distracting cares, and to leave them at leisure for the duties of their station; so that they may be wholly employed therein, and avail themselves of every opportunity, by acts of kindness, to gain the good-will of the people, and to draw their attention.