Deuteronomy 17:4-6

Revised Standard Version

⁴ and it is told you and you hear of it; then you shall inquire diligently, and if it is true and certain that such an abominable thing has been done in Israel, ⁵ then you shall bring forth to your gates that man or woman who has done this evil thing, and you shall stone that man or woman to death with stones. ⁶ On the evidence of two witnesses or of three witnesses he that is to die shall be put to death; a person shall not be put to death on the evidence of one witness.