Deuteronomy 19:18 in the King James Version
And the judges shall make diligent inquisition: and, behold, if the witness be a false witness, and hath testified falsely against his brother;
Context
17 then both the men, between whom the controversy is, shall stand before the LORD, before the priests and the judges who shall be in those days;
18 and the judges shall make diligent inquisition; and behold, if the witness is a false witness, and has testified falsely against his brother,
19 then you shall do to him as he had thought to do to his brother. So you shall remove the evil from among you.