Numbers 35:29-31

New Revised Standard Version, Anglicised Catholic Edition

²⁹ These things shall be a statute and ordinance for you throughout your generations wherever you live.

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.