Concerning them, see Numbers, chapter 35, and Joshua chapter 21.
"The suburbs of the cities of the Levites were three thousand cubits on every side; viz. from the walls of the city, and outwards; as it is said, 'From the walls of the city and outwards a thousand cubits: and thou shalt measure from without the city two thousand cubits' (Num 35:4,5). The former thousand were the suburbs, and the latter two thousand were for fields and vineyards. They appointed the place of burial to every one of those cities to be without these bounds; for within them it was not lawful to bury a dead corpse." Do you ask the reason? It was not so much for the avoiding pollution, which might be contracted from a sepulchre, as by reason of the scribes' curious interpretation of the law, that saith, The suburban lands of these cities were given to the Levites for their cattle and oxen, "and for all their living" (creatures), Numbers 35:3:--therefore, say they, not for the dead or for burial.
All the cities of the Levites were cities of refuge; but with this distinction from those six which were properly so called; that those six afforded refuge to every one that dwelt in them, whether he betook himself thither for that end or no: but the other Levitical cities were not so. And also, that the unwitting manslayer, flying to those six cities, dwelt there at free cost, without paying any rent for his house; but in the other Levitical cities he lived not at free cost.
Those forty-eight cities of the Levites were so many universities, where the ministerial tribe, distributed in companies, studied the law, became learned; and thence scattered through the whole nation, dispersed learning and the knowledge of the law in all the synagogues.
Two things are, not without good reason, to be observed here, which, perhaps, are not seriously enough observed by all.
I. The settled ministry of the church of Israel was not prophets, but priests and Levites, Malachi 2:7. For it was not seldom when there were no prophets; and the prophets send the people to the priests for instruction, Haggai 2:11, and Malachi, in the place mentioned already.
II. That tithes were granted to the priests and Levites, not only when they ministered at the altar or in the Temple, but when they studied in the universities and preached in the synagogues.
Behold the method of God's own institution. God chooseth Israel to be a peculiar people to himself: to this chosen people he gives a law and a clergy: on the clergy he enjoins the study of the law: to their studies he suits academical societies: on the universities he bestows lands and tithes: on the synagogues he bestows tithes and university-men.
And the schools of the prophets were little universities, and colleges of students. For their governor they had some venerable prophet, inspired with the Holy Spirit, and that partook of divine revelations. The scholars were not inspired indeed with the same prophetical spirit, but received prophecies from the mouth of their master. He revealed to them those things that were revealed to him, of the will of God and the state of the people, of the times and events of Israel, and above all, of the mysteries of the gospel; of the Messias, of his coming, times, death, resurrection, and those things that were to be done by him.
In these small universities, "the prophets, who prophesied of the grace that should come (as the apostle Peter speaks), inquired diligently of salvation; searching what, or what manner of time that was, which was pointed out by the Spirit of Christ that was in them, when he foretold the sufferings of Christ, and the glory that should follow." These things, not to be fetched out by the mere and bare study of the law, were here taught; and so the studies of the law and gospel together rendered the minister of the divine word complete.