40. Violating a Torah Law
Yesodei HaTorah 9:2
If no prophet is equal to Moses, what is meant when the Torah says, “I will appoint a prophet like you from among their brethren; I will place My words in his mouth and he will speak...” (Deuteronomy 18:18)? The intention is not that the future prophet will come to innovate a religion. Rather, he will command the people to observe the mitzvos of the Torah, and he will warn against violating them. We see this from the last prophet, who said in God’s Name, “Remember the Torah of Moses, My servant” (Malachi 3:22).
A prophet may command us to do something that is neither required nor prohibited by the Torah, such as to travel to a certain place or not to travel there, to wage war or not, to build a wall or not, etc. In such a case, it is a mitzvah to listen to him. One who disregards a prophet’s instructions is liable to a Heavenly death as per Deuteronomy 18:19, “If one does not heed My words that he (the prophet) speaks in My name, I will hold him responsible.”
Yesodei HaTorah 9:3
If a prophet violates instructions he received in his own prophetic message, or if he refrains from delivering his prophecy, he is also liable for a Heavenly death because regarding all three cases it says, “I will hold him responsible.”
If a proven prophet instructs us to violate one of the mitzvos of the Torah, or even many mitzvos, whether they are “big” or “small” mitzvos, if it is a temporary measure, we are required to listen to him. The early Sages passed on, as part of the oral tradition, that if a prophet commands us to violate the mitzvos of the Torah, as Elijah did on Mount Carmel, we listen to him in any matter except for idolatry. This only applies when his command is a temporary measure.
What Elijah did on Mount Carmel was to offered a sacrifice outside the Temple. Even though it was in Jerusalem, one who offers a sacrifice outside the Temple is liable to the penalty of kareis (spiritual excision). However, since Elijah was recognized as an authentic prophet, it was a mitzvah to listen to him. The obligation to heed a prophet applies in such cases. If the people had asked Elijah how they were permitted to violate a Torah law, he would have told them that yes, offering a sacrifice outside the Temple normally carries the penalty of kareis, as per the Torah that Moses taught. Elijah’s case was an exception to the general rule because he was offering his sacrifice outside the Temple at God's command in order to refute the prophets of the idol Ba’al.
Similarly, if any prophet commands us to violate a mitzvah as a temporary measure, we are required to listen to him. But if he tells us that a mitzvah has been permanently abolished, he is liable for the capital punishment of strangulation because the Torah has told us that it is “for us and our children forever” (Deuteronomy 29:28).