Numbers 35:31-33

New King James Version

³¹ Moreover you shall take no ransom for the life of a murderer who is guilty of death, but he shall surely be put to death. ³² And you shall take no ransom for him who has fled to his city of refuge, that he may return to dwell in the land before the death of the priest. ³³ So you shall not pollute the land where you are; for blood ^(A)defiles the land, and no ^[a]atonement can be made for the land, for the blood that is shed on it, except ^(B)by the blood of him who shed it.