Parallel
Numbers 35:30
Jewish Publication Society 1917 · Berean Standard Bible
Whoso killeth any person, the murderer shall be slain at the mouth of witnesses; but one witness shall not testify against any person that he die.
If anyone kills a person, the murderer is to be put to death on the testimony of the witnesses. But no one is to be put to death based on the testimony of a lone witness.