Mishneh Torah, Foundations of the Torah 9

Sugya Map

• Issue: The immutability of the Torah (Torah Min HaShamayim) and the precise boundaries of prophetic authority, particularly concerning adding, subtracting, or modifying mitzvot. This includes defining a "false prophet" (navi sheker) and the parameters of a temporary abrogation of Halacha (hora'at sha'ah).
• Nafka Mina(s):
  • Identifying a navi sheker and their corresponding capital punishment (chenek).
  • Distinguishing between legitimate prophetic directives (hora'at sha'ah) and heretical claims.
  • Understanding the eternal nature of mitzvot (netzach Yisrael).
  • Defining the scope of Lo Bashamayim Hi (Devarim 30:12) in relation to prophetic innovation and Rabbinic authority.
• Primary Sources:
  • Devarim 13:1 (Lo Tosif v'Lo Tigra).
  • Devarim 29:28 (Nistarot l'Hashem Elokeinu v'haNiglot lanu u'l'baneinu ad olam).
  • Devarim 30:12 (Lo Bashamayim Hi).
  • Devarim 18:18-19 (Prophet like Moshe, listen to him).
  • Malachi 3:22 (Zichru Torat Moshe Avdi).
  • Bava Metzia 59b (Lo Bashamayim Hi in the oven of Achnai).
  • Sanhedrin 89a-90a (laws of navi sheker and hora'at sha'ah).
  • Temurah 16a (Yehoshua and Lo Bashamayim Hi).

Text Snapshot

The Rambam, in Hilchot Yesodei HaTorah, outlines the foundational principle of Torah's eternal nature and the strict limits of prophecy.

• "דבר ברור ומפורש בתורה שהיא מצוה עומדת לעולם ולעולמי עולמים אין לה לא שינוי ולא גרעון ולא תוספת..."
  • Mishneh Torah, Foundations of the Torah 9:1. This opening declares the Torah's absolute immutability, using strong double superlatives (l'olam u'l'olmei olamim) for eternity, and explicitly precluding "change, diminution, or addition." The choice of "מצוה" (commandment) in the singular suggests the entire body of Torah is a singular, unchanging command.
• "...ונאמר לא בשמים היא. הא למדת שאין נביא רשאי לחדש דבר מעתה."
  • Mishneh Torah, Foundations of the Torah 9:1. The Rambam directly links the phrase Lo Bashamayim Hi (Devarim 30:12) – "It is not in the heavens" – to the prohibition against a prophet introducing new mitzvot. This is crucial, as this phrase is famously used in Bava Metzia 59b to assert Rabbinic interpretive authority, but here it establishes the finality of the Mosaic revelation.
• "לפיכך אם יעמוד איש יהודי או גוי ויעשה אות או מופת ויאמר שה' שלחו להוסיף מצוה אחת או לגרוע מצוה אחת או לפרש במצוה מן המצות פירוש שלא שמענו או שאמר שהמצות שנצטוו בהן ישראל אינן לעולם אלא לפי שעה - הרי זה נביא שקר..."
  • Mishneh Torah, Foundations of the Torah 9:1. The Rambam enumerates four specific categories of false prophetic claims, all leading to the verdict of navi sheker: adding, subtracting, reinterpreting contrary to tradition, or declaring mitzvot temporary. The emphasis on "פירוש שלא שמענו" (an interpretation we have not heard) highlights the supreme authority of Mesora (tradition) in understanding Torah.
• "כשם שנביא שצונו לעבור על דברי תורה או על דברים הרבה לפי שעה מצוה לשמוע לו... חוץ מעבודת כוכבים..."
  • Mishneh Torah, Foundations of the Torah 9:2. This halacha introduces the concept of hora'at sha'ah – a temporary prophetic command to transgress a mitzvah. The crucial caveat: it must be "לפי שעה" (temporary) and explicitly "חוץ מעבודת כוכבים" (excluding idolatry). This forms the primary tension in the sugya.

Readings

Shorshei HaYam – Defining the "False Prophet's" Demise and Deception

The Shorshei HaYam (on MT, Foundations of the Torah 9:1:1) delves into the mechanics and rationale of the navi sheker's punishment. He notes the Rambam's ruling of chenek (strangulation) for a false prophet, aligning it with Rav Chisda's opinion in Sanhedrin 89a, as understood by the Lechem Mishneh. The Shorshei HaYam explains that a general death penalty in Torah implies chenek, derived from Devarim 18:20 (asher yazid ledaber davar). He challenges the Kessef Mishneh's assertion that this verse primarily concerns idolatry, clarifying that for Avodah Zarah, the punishment is sekilah (stoning), derived from a gezeirah shavah of "sorah sorah" (Devarim 13:6, 18:20) in Sanhedrin 90a, while for other mitzvot, chenek is universally agreed upon.

A significant chiddush from Shorshei HaYam addresses the Rambam's clause: "or to explain a mitzvah in a manner which differs from the tradition received from Moses." The Lechem Mishneh found this problematic, suggesting it might imply a "partial nullification" (mekayem miktzat u'mevatel miktzat) which some opinions in the Gemara exempt. The Shorshei HaYam robustly rejects this, arguing that such a prophet's reinterpretation (e.g., tefillin mean "paper with Genesis") is not a partial nullification but a complete uprooting (oker hamitzvah legamrei) of the mitzvah's essence. Thus, it squarely falls under the category of denying Moshe's prophecy and warrants chenek. He further reconciles Rambam's statements across different chapters (e.g., Hilchot Avodah Zarah) by clarifying Rashi's understanding in Sanhedrin 89a, emphasizing that the verse ki yazid refers to prophesying "what he did not hear" (mitnabeh ma shelo shama) in a general sense, not specifically to uprooting mitzvot, which has its own, more severe, penalties.

Tziunei Maharan – The Source of 'Lo Bashamayim Hi'

The Tziunei Maharan (on MT, Foundations of the Torah 9:1:1) focuses on the Rambam's use of Lo Bashamayim Hi (Devarim 30:12) as the foundational proof that "a prophet can no longer add a new precept [to the Torah]." He notes the Kessef Mishneh's observation that this verse is famously cited in Bava Metzia 59b, regarding the "oven of Achnai" dispute, to establish that Halacha is decided by human Sages, not by divine intervention. The Tziunei Maharan then points to Temurah 16a, where the Gemara explicitly states that Yehoshua used Lo Bashamayim Hi in response to Moshe's forgotten halachot, signifying that divine revelation for new halachot had ceased. While Temurah 16a also cites V'Eileh HaMitzvot (Devarim 6:1) for the same principle, the Tziunei Maharan, following the Lechem Mishneh, explains that the Rambam chose Lo Bashamayim Hi because it is "מבואר יותר" (clearer) in its implication of finality, and was indeed the verse used by Yehoshua directly in the context of lost halachot. This reading highlights Rambam's precision in selecting scriptural proofs that directly and unambiguously support his theological claim about the conclusion of direct prophetic legislative authority.

Seder Mishnah – Against the Mutability of Torah

The Seder Mishnah (on MT, Foundations of the Torah 9:1:1) presents a profound critique of the Sefer HaIkkarim (R' Yosef Albo), which posits that while the Torah has not changed, it is possible for God to change mitzvot. The Seder Mishnah finds this theoretical possibility deeply problematic, arguing that it undermines the entire halacha of navi sheker. If mitzvot could change, how could we definitively declare a prophet false who claims such a change? Perhaps God has indeed decided to change a mitzvah through this prophet? He states: "היאך אפשר להעלות על הדעת שיש מציאות שתשתנה אחת ממצות ה' ... כיון שהוא זה דבר אפשרי איכה נדע את הדבר אשר לא דברו הש"י ושבשקר דברו הנביא?" (How can one conceive of a reality where one of God's commandments could change... since this is a possible thing, how shall we know the matter that Hashem has not spoken and that the prophet spoke falsely?). This is a core chiddush – the very definition of a false prophet depends on the impossibility of Torah change.

The Seder Mishnah further refutes Sefer HaIkkarim's attempts to justify the theoretical possibility of change. He challenges Albo's reliance on the idea that all Israel heard God's command to Moshe, "V'Ata Po Amode Imadi" (Devarim 5:28), as proof of Moshe's unique authority to receive all future mitzvot. The Seder Mishnah argues that the plain reading (peshitut mashma'ut hakra) suggests only Moshe heard this, not the entire nation. He then critiques Albo's historical examples of change (e.g., Yeremiyahu changing the calendar, or Noach being permitted meat after Adam's prohibition). Regarding Noach, the Seder Mishnah offers a sophisticated terutz by suggesting that God spoke directly to Noach and his sons, thus abrogating Adam's command directly from the "greater prophet" (God) rather than through Noach as a "lesser prophet." However, he ultimately rejects this terutz for its inherent dechika (strain), particularly regarding Cham and the women, concluding that Albo's entire premise of mutable mitzvot is "תמוהים בעיני" (puzzling in my eyes).

Tzafnat Pa'neach – Nuances of Hora'at Sha'ah

The Tzafnat Pa'neach (on MT, Foundations of the Torah 9:1:1) briefly touches on the Rambam's example of Elijah's sacrifice on Mount Carmel as a hora'at sha'ah. He cites the Yerushalmi (Megillah 1:1) which suggests that the prohibition of bamot (altars outside the Temple) was initially given with the understanding that it could be temporarily permitted by a prophet. He further distinguishes between a private act of hora'at sha'ah (which might not require a publicly recognized prophet, citing Keritot 12b) and a public one, which certainly does. In a later, extensive commentary (on MT, Foundations of the Torah 9:1:2), the Tzafnat Pa'neach expands on the concept of netzach Yisrael and hora'at sha'ah, exploring whether the shiurim (measurements) of mitzvot are eternally fixed or dynamic, and how prophetic commands relate to the essential nature of Torah law. He notes that the specific case of Elijah on Carmel is understood by the Yerushalmi and Sifrei (Devarim, Piska 84) not merely as a transgression of shchuței chutz, but as a legitimate, temporary permission to offer sacrifices on a bamah by prophetic command, making it a valid korban for that specific time and purpose. This underscores that hora'at sha'ah does not deem the act a sin, but transforms it into a temporary mitzvah.

Friction

The Central Kushya: Immutability vs. Temporary Transgression

The most acute tension in this sugya lies in reconciling the Rambam's absolute declaration of the Torah's immutability – "אין לה לא שינוי ולא גרעון ולא תוספת" (it has no change, diminution, or addition) – with the subsequent allowance for a prophet to command a temporary transgression of Torah law (hora'at sha'ah). If the Torah is truly immutable and eternal, how can God, through a prophet, command its temporary abrogation? This appears to be a direct "שינוי" (change), albeit temporary, to the Torah's directives. The language "צונו לעבור על דברי תורה" (commanded us to transgress the words of Torah) seems to fly in the face of the foundational principle of Lo Tosif v'Lo Tigra. How can the very same divine authority that established the eternal law authorize its temporary suspension without compromising its unchangeable nature?

The Best Terutz: Hora'at Sha'ah as a Divine Exception, Not Abrogation

The Rambam himself provides the essential terutz within the very fabric of the halachot. A hora'at sha'ah is not an abrogation or permanent change to the Torah's law, but rather a divinely ordained, temporary suspension of its application for a specific purpose. The underlying mitzvah remains fully in force, ad olam. The prophet, in commanding a temporary transgression, is not saying "this mitzvah is nullified" (which would incur chenek), but "God commands you to perform this specific act, now, for this reason."

This distinction is critical:

1. Immutability of the Law: The law itself (issur bamot, lo tishchat) remains unchanged and eternal. The navi does not declare it null and void.
2. Divine Command: The hora'at sha'ah is itself a new, temporary mitzvah from God, superseding the standing prohibition for that moment. As the Rambam states, "מצוה לשמוע לו" (it is a mitzvah to listen to him). The act, though outwardly a transgression, is halachically transformed into an act of obedience to a higher, temporary divine will.
3. Purpose: Such commands are given for specific, often urgent, divine purposes, such as to solidify God's name, prove the prophet's authenticity against false prophets (as with Elijah on Carmel), or save Jewish lives. The Rambam emphasizes Elijah's act was "כדי להפר עצת נביאי הבעל" (to disprove the counsel of the prophets of Ba'al).
4. Limitations: The hora'at sha'ah is strictly "לפי שעה" (temporary) and explicitly excludes Avodah Zarah. This limitation highlights that the core theological principles (God's unity, the eternal covenant) can never be suspended, even temporarily. As the Rambam concludes, even great wonders cannot validate idolatry, for such a prophet "בא להכחיש נבואתו של משה" (comes to deny the prophecy of Moses) (MT, Foundations of the Torah 9:2).

The Seder Mishnah's deep dive into the Sefer HaIkkarim's position reinforces this: if the mitzvah itself could change, even theoretically, the very definition of a false prophet would collapse. The fact that a prophet commanding a permanent change is a navi sheker (and subject to chenek) inherently proves the mitzvah's eternal nature. Hora'at sha'ah is thus not a change to the Torah, but an additional, temporary, specific directive within the framework of the unchanging Torah.

Intertext

Devarim 13:1 (Lo Tosif v'Lo Tigra)

The Rambam explicitly cites Devarim 13:1, "All these matters which I command to you, you shall be careful to perform. You may not add to it or diminish from it," as a foundational proof for the Torah's immutability. This verse serves as the bedrock prohibition against any prophet, Beit Din, or individual altering the number or essence of mitzvot. The Sifrei Devarim ad loc. elaborates on the precise scope of "adding" or "diminishing," clarifying that it refers to the mitzvot themselves, not to gezeirot (rabbinic decrees) or takanot (rabbinic enactments) that fence the Torah or facilitate its observance. The Rambam's entire edifice concerning the navi sheker and the nature of hora'at sha'ah is built upon this explicit biblical injunction, defining what constitutes legitimate religious innovation versus heretical deviation.

Bava Metzia 59b (Lo Bashamayim Hi)

While the Rambam uses Lo Bashamayim Hi (Devarim 30:12) in Yesodei HaTorah 9:1 to signify that no prophet can add new mitzvot, its most famous appearance is in Bava Metzia 59b, in the Aggadah of the oven of Achnai. There, Rabbi Yehoshua employs this phrase against a Bat Kol (Heavenly Voice) that sides with Rabbi Eliezer in a halachic dispute. Rabbi Yehoshua declares that "לא בשמים היא" – the Torah "is not in the heavens"; once given, its interpretation and application are entrusted to human Sages, decided by majority rule. This demonstrates a parallel, yet distinct, application of the principle of finality of revelation. In Yesodei HaTorah, it closes the door to new divine legislation; in Bava Metzia, it transfers the authority of Halachic interpretation to the Rabbinic court, ensuring that Halacha remains a dynamic, yet bounded, human endeavor. Both uses reinforce the idea that direct, extra-terrestrial intervention in the halachic process ceased at Sinai.

Psak/Practice

The Rambam's exposition here forms a meta-halachic bedrock for Jewish thought and practice.

1. Immutability of Torah: The fundamental principle that the Torah, as given at Sinai, is eternal and unalterable is a Yesod HaEmunah (fundamental principle of faith). This means that no individual, group, or even subsequent prophet can introduce new mitzvot or permanently abolish existing ones. This guards against claims of "new religions" or "reformed" Judaism that purport to transcend or supersede the Mosaic covenant.
2. Prophetic Authority & Its Limits: The Rambam delineates the precise boundaries of prophetic authority. A prophet can command in matters muttar (permitted) or issue a hora'at sha'ah (temporary suspension of a mitzvah) for specific divine purposes (excluding Avodah Zarah). Anything beyond these, particularly claiming permanent change to Torah, constitutes navi sheker. This provides clear criteria for assessing prophetic claims, a critical heuristic for safeguarding tradition.
3. Role of Tradition (Mesora): The inclusion of "to explain a mitzvah in a manner which differs from the tradition received from Moses" as a category of false prophecy underscores the paramount importance of Mesora. True understanding of Torah is not derived from novel interpretations contradicting the received tradition, but by careful transmission and elucidation of that tradition. This has profound implications for how Halacha is studied and applied, grounding it in an unbroken chain from Sinai.

Takeaway

The Torah is an immutable, eternal divine covenant, and prophetic authority is strictly bounded, serving to uphold and clarify its laws, never to permanently alter them. The concept of hora'at sha'ah allows for temporary, divinely commanded deviations from mitzvot (excluding Avodah Zarah) for specific purposes, but these are exceptions that prove the rule of the Torah's everlasting nature, not abrogations.