Numbers 35 provides homes for the Levites: forty-eight cities with pasture lands, scattered among the tribes so that the priests' helpers would live throughout Israel. Six of them were to be cities of refuge, three east of the Jordan and three in Canaan. These six cities shall be refuge for the children of Israel, for the stranger, and for the foreigner living among them, that everyone who kills any person unwittingly may flee there.
The law carefully distinguished murder from accidental killing. Striking someone with an iron tool, a stone, or a weapon out of hatred was murder. But if someone pushed another suddenly without hostility, or dropped a stone without seeing him, the congregation would judge between him and the avenger of blood. If the killing was accidental, the congregation would restore him to the city of refuge. No one could be put to death on the testimony of one witness, and no ransom could be taken for a murderer.
The manslayer stayed in the city until the death of the high priest, who was anointed with the holy oil. Then he could return home. The chapter closes: You shall not defile the land which you inhabit, where I dwell; for I, Yahweh, dwell among the children of Israel. Many Christians see Jesus, our great High Priest, as the true refuge. Hebrews 6:18 speaks of those who have fled for refuge to take hold of the hope set before us. This is a Christian reading, not something Numbers states directly.