Numbers 35:30-34

Towns for the Levites

³⁰“All murderers must be put to death, but only if evidence is presented by more than one witness. No one may be put to death on the testimony of only one witness. ³¹Also, you must never accept a ransom payment for the life of someone judged guilty of murder and subject to execution; murderers must always be put to death. ³²And never accept a ransom payment from someone who has fled to a city of refuge, allowing a slayer to return to his property before the death of the high priest. ³³This will ensure that the land where you live will not be polluted, for murder pollutes the land. And no sacrifice except the execution of the murderer can purify the land from murder. ³⁴You must not defile the land where you live, for I live there myself. I am the Lord, who lives among the people of Israel.”