Numbers 35:30-32

21st Century King James Version

³⁰ Whoso killeth any person, the murderer shall be put to death by the mouth of witnesses; but one witness shall not testify against any person to cause him to die.

³¹ Moreover ye shall take no payment for the life of a murderer who is deserving of death, but he shall be surely put to death.

³² And ye shall take no payment for him that has fled to the city of his refuge, that he should come again to dwell in the land until the death of the priest.