Joshua 20:4-6

He shall flee to one of these cities, and shall stand at the entrance of the gate of the city and explain his case to the elders of that city; and they shall take him into [the protection of] the city and give him a place [to stay], so that he may live among them. If the blood avenger pursues him, they shall not hand the offender (manslayer) over to him, because he killed his neighbor unintentionally and without premeditation and did not hate him beforehand. He shall live in that city until he has stood before the congregation for judgment [and if acquitted of murder he must stay there], until the death of the one who is the high priest in those days. Then the offender (manslayer) shall return to his own city and his own house from which he fled.’ ”