הלכה על דברים 5:17

He prohibited giving false testimony. And that is His saying, "You shall not testify against your neighbor false testimony" (Exodus 20:13). And this has been repeated with a different language; and that is His saying, "vain testimony" (Deuteronomy 5:17). And the Torah has already decreed about this negative commandment, "You shall do to him as he schemed" (Deuteronomy 19:19). And the language of the Mekhilta (Mekhilta d'Rabbi Yishmael 20:13:3) is "'You shall not testify against your neighbor' - that is the prohibition for scheming witnesses." And there is also lashes for [violation of] this negative commandment, as is explained at the beginning of Makkot (Makkot 2b). (See Parashat Yitro; Mishneh Torah, Testimony 17.)