When can one listen to a Navi who says to disobey the Torah? The gemara in Sanhedrin (89) tells us that the reason Bnei Yisrael listed to Eliyahu at Har haKarmel to offer a korban outside the Bais HaMikdash and the reason Yitzchak listened to Avraham to agree to the akeidah was because Eliyahu and Avraham were ‘muchzak’, they already had established their bona fides as Nevi’im. The gemara in Yevamos (90) asks why we cannot derive from this halacha that Bais Din also has the right to uproot a mitzvah b’kum v’aseh, and answers that the law for a Navi is different because the Torah specifically mandates “eilav tishma’un’, to listen to the Navi. Asks the gemara further, why not use this as a binyan av for Bais Din as well (see Tosfos), and answers that the case of Eliyahu and Avraham was l’migdar milsa, just an emergency measure, which would be permissible for B”D as well, but not as a general rule. Tosfos puts the two gemaras together and writes that emergency measures allow the Navi license to act, but the validity of the Navi’s assessment of what constitutes ‘l’migdar milsa’ can be made only by a Navi who is muchzak.
Tosfos asks: how could the gemara in Yevamos try to derive from the Navi’s right to override Torah law that Bais Din could do so as well – the Navi acts under the direct command of G-d, which Bais Din does not have?! Tosfos (Sanhedrin 89b) answers that the gemara’s assumption is that the Navi does not always have a direct command from G-d either, but must still be obeyed in even violation of Torah law based on the Navi’s own assessment and da’as of what is correct. The Minchas Chinuch points out that from the Rambam (Yesodei haTorah 9:6) it seems that the mitzvah to obey the Navi is limited to where the Navi speaks “b’dvar Hashem”, through direct prophecy.
There seems to be a fundamental issue at the core of this debate: is the gavra of Navi a person invested with authority who must be obeyed even in matters that he intuits based on his da’as, or is it nevuah, the cheftza of prophecy, which we are commanded to obey? Reflecting back on the issue raised yesterday, R’ Soloveitchik’s distinction between the cheftza of nevuah and the cheftza of Torah seems to assume the latter approach to the mitzvah. However, according to the former approach, that the person of the Navi is invested with authority, irrespective of the subject matter of the Navi’s command, the mitzvah of obeying the Navi still might apply.