On the plains of Moab, by the Jordan, the Lord tells Moses that the Israelites are to give the Levites cities to live in from the inheritance of each tribe, with pastureland around them for their livestock. There will be forty-eight cities, and the tribes with more will give more. Six of them will be cities of refuge: three east of the Jordan and three in Canaan.
The cities of refuge allow someone who kills a person unintentionally to flee from the vengeance of the victim's relative, called the avenger of blood, until he stands trial before the congregation. The chapter distinguishes murder, done with a deadly object, in hatred or by ambush, which deserves death, from manslaughter, a blow struck without enmity or intent. The avenger may put the murderer to death, but the city protects the one who killed unintentionally. He must stay in it until the death of the high priest, and if he leaves before then, the avenger may kill him without guilt.
To sentence someone to death there must be at least two witnesses, and no ransom is accepted for the life of a murderer or to spare someone who killed unintentionally from exile. At the end the Lord gives the reason: blood defiles the land, which can only be cleansed by the blood of the one who shed it, and they must not defile the land where the Lord himself dwells among the Israelites.