Albert Barnes Commentary Numbers 35

Suburbs - Rather, “pasture-grounds,” required for their large cattle, for their sheep and goats, and for all their beasts whatever they might be (Numbers 35:3).

From without the city — Omit “from.” The demarcation here intended would run parallel to the wall of the city, outside which it was made. To guard against any restrictions of area, due to such causes as the irregular forms of the cities or the physical obstacles of the ground, it was ordained that the suburb should, alike on north, south, east, and west, present, at a distance of one thousand cubits (or, nearly one-third of a mile) from the wall, a front not less than two thousand cubits in length; and, by joining the extremities of these measured fronts according to the nature of the ground, a sufficient space for the Levites would be secured.

The Levitical cities were in a special manner the Lord’s; and therefore the places of refuge, where the manslayer might remain under the protection of a special institution devised by divine mercy, were appropriately selected from among them. No doubt also the Priests and Levites would be the fittest persons to administer the law in the doubtful cases which would be sure to occur (compare Numbers 35:24 note).

Nine cities were eventually given to the Levites from the large joint inheritance of Judah and Simeon; three were taken from the territory of Naphtali, and the other tribes gave four apiece.

The avenger - Hebrew גאל gā'al — a term whose original meaning is uncertain. The very obscurity of its etymology testifies to the antiquity of the office it denotes. That office rested on the principle of Genesis 9:6, whoso sheddeth man’s blood, by man shall his blood be shed. The unwritten code of the East conceded to the nearest kinsman of a murdered man the right of avenging the blood that had been shed.

Such primitive justice necessarily involved grave evils. It gave no opportunity for the person charged with the crime to establish his innocence; it recognized no distinction between murder, manslaughter, and accidental homicide; and it perpetuated family blood-feuds, as the avenger of blood was liable to be treated in turn as a murderer by the kinsman of the man whom he had killed.

These grievances could not be removed as long as there was no central government, but they could be mitigated; and to do this was the purpose of the institution in the text .

Among the Arab tribes, who are under the control of no central authority, the practice of blood-revenge remains in full force to the present day.

The congregation - that is, the local court, consisting of the elders of the city (Joshua 20:4).