Deuteronomy 19:18

The judges shall inquire diligently , and if the witness is a false witness and has accused his brother falsely ,

The judges must make a thorough investigation, and if the witness proves to be a liar, giving false testimony against a fellow Israelite,

And the judges shall make diligent inquisition : and, behold, if the witness be a false witness, and hath testified falsely against his brother;