NumbersChapter 35

"Command the Israelites to give the Levites towns to live in out of the inheritance they possess, and give the Levites pastureland around those towns.
The pastureland around the towns you give the Levites shall extend a thousand cubits out from the town wall on every side.
Outside the town, measure two thousand cubits on the east side, two thousand on the south, two thousand on the west, and two thousand on the north, with the town in the center. This will be the pastureland for their towns.
Among the towns you give the Levites there shall be six cities of refuge, to which anyone who has killed a person may flee. To these add forty-two more towns.
In all you are to give the Levites forty-eight towns, together with their pastureland.
The towns you give from the holdings of the Israelites shall be taken in proportion: from a larger tribe take more, from a smaller tribe take fewer. Each tribe is to give the Levites towns according to the size of its inheritance."
"Speak to the Israelites and say to them: When you cross the Jordan into the land of Canaan,
select certain towns to be your cities of refuge, to which a person who has killed someone unintentionally may flee.
They will be your refuge from the avenger, so that the one accused of murder does not die until he has stood trial before the assembly.
The six towns you give shall be your cities of refuge.
Give three of them on the east side of the Jordan and three in the land of Canaan as cities of refuge.
These six towns will be a place of refuge for the Israelites, for the foreigner, and for the stranger living among them, so that anyone who kills a person unintentionally may flee there.
Or if a man has a wooden object in his hand that can kill, and he strikes someone so that he dies, he is a murderer; the murderer must be put to death.
or in hostility strikes him with his hand so that he dies, the one who struck him must be put to death; he is a murderer. The avenger of blood shall kill the murderer when he meets him.
or without seeing him drops on him a stone that can kill, and he dies—though he was not his enemy and did not intend him harm—
The assembly is to protect the one accused of murder from the avenger of blood and send him back to the city of refuge to which he fled. He must stay there until the death of the high priest who was anointed with the holy oil.
and the avenger of blood finds him outside the boundary of his city of refuge and kills him, the avenger is not guilty of bloodshed;
for the accused must remain in his city of refuge until the death of the high priest. Only after the death of the high priest may he return to his own property.
These are to be legal statutes for you throughout your generations, wherever you live.
Anyone who kills a person is to be put to death on the testimony of witnesses; no one is to be put to death on the testimony of a single witness.
Do not accept a ransom for the life of a murderer who deserves to die; he must surely be put to death.
Do not pollute the land where you live. Bloodshed pollutes the land, and no atonement can be made for the land on which blood has been shed except by the blood of the one who shed it.
Do not defile the land where you live and where I dwell, for I, the LORD, dwell among the Israelites."