Numbers 35:28-30

Complete Jewish Bible

²⁸ because he must stay in his city of refuge until the death of the cohen hagadol. But after the death of the cohen hagadol the killer may return to the land he owns. ²⁹ These things shall constitute your standard for judgment through all your generations, wherever you live.

³⁰ “‘If anyone kills someone, the murderer is to be put to death upon the testimony of witnesses; but the testimony of only one witness will not suffice to cause a person to be put to death.