Numbers 35:31-33

Evangelical Heritage Version

³¹ You are not to accept a ransom for the life of a murderer who is guilty of death, because he must certainly be put to death.

³² You are not to accept a ransom for the one who has fled to a city of refuge in order to allow him to return to live in his land before the death of the priest.

³³ So you are not to pollute the land where you are, because bloodshed pollutes the land. No atonement can be made for the land where blood has been shed except by the blood of the one who shed it.