41. Claims of the False Prophet

Yesodei HaTorah 9:4

If a prophet tries to abolish something that was transmitted as part of our oral tradition, or if he claims regarding a Torah law that God told him to render a certain judgment, or if he claims to know the law in a particular matter saying that it follows a certain opinion, this person is a false prophet and is liable to the penalty of strangulation. This is true even if he performs a wonder because he denies the Torah, which has already told us that the law is no longer in Heaven (Deuteronomy 30:12). However, if he says that the matter only applies for a limited time, then he should be heeded in all matters.

Yesodei HaTorah 9:5

The previous law only applies to mitzvos other than idolatry. When it comes to idolatry, we would not listen to a prophet even as a temporary measure. Even if he performs miracles, saying that God commanded him to worship idols only on a particular day or at a particular time, he is considered to have spoken perversely against God (a reference to Deuteronomy 6:13). Regarding this matter, the Torah has told us that even “if he performs a sign or a miracle... do not listen to the words of this prophet... because he has spoken perversely against Hashem, your God" (Deuteronomy 13:3-6). This person denies the prophecy of Moses, so he is definitely a false prophet, and all of his signs were obviously just tricks. He is liable to the penalty of strangulation.