Numbers 35:27

23Or with any stone, wherewith a man may die, seeing him not, and cast it upon him, that he die, and was not his enemy, neither sought his harm:

24Then the congregation shall judge between the slayer and the revenger of blood according to these judgments:

25And the congregation shall deliver the slayer out of the hand of the revenger of blood, and the congregation shall restore him to the city of his refuge, whither he was fled: and he shall abide in it unto the death of the high priest, which was anointed with the holy oil.

26But if the slayer shall at any time come without the border of the city of his refuge, whither he was fled;

27And the revenger of blood find him without the borders of the city of his refuge, and the revenger of blood kill the slayer; he shall not be guilty of blood:

28Because he should have remained in the city of his refuge until the death of the high priest: but after the death of the high priest the slayer shall return into the land of his possession.

29So these things shall be for a statute of judgment unto you throughout your generations in all your dwellings.

30Whoso killeth any person, the murderer shall be put to death by the mouth of witnesses: but one witness shall not testify against any person to cause him to die.

31Moreover ye shall take no satisfaction for the life of a murderer, which is guilty of death: but he shall be surely put to death.