Numbers 35:30-32

New Revised Standard Version, Anglicised Catholic Edition

³⁰ If anyone kills another, the murderer shall be put to death on the evidence of witnesses; but no one shall be put to death on the testimony of a single witness. ³¹ Moreover, you shall accept no ransom for the life of a murderer who is subject to the death penalty; a murderer must be put to death. ³² Nor shall you accept ransom for one who has fled to a city of refuge, enabling the fugitive to return to live in the land before the death of the high priest.