Mishneh Torah, Negative Mitzvot 1-365

Sugya Map

• Issue: The Rambam's enumeration of the 613 mitzvot and, critically, his foundational approach to distinguishing between mitzvot d'Oraita (Biblical) and mitzvot d'Rabbanan (Rabbinic). This includes his explanation of how Rabbinic enactments avoid transgressing the prohibition of Lo Tosif u'Lo Tigra ("You shall not add to it, nor diminish from it") and are nonetheless binding.
• Nafka Mina(s):
  • The halakhic weight and enforceability of Rabbinic decrees versus Biblical commands (e.g., safek d'Oraita l'chumra, safek d'Rabbanan l'kula).
  • The definition and scope of the Lo Tosif prohibition.
  • The source and nature of rabbinic authority (samchut chachamim).
  • The criteria for what constitutes one of the 613 mitzvot.
• Primary Sources:
  • Mishneh Torah, Negative Mitzvot 1-365 (Concluding remarks, particularly the methodological discussion at the end of the text provided).
  • Devarim 13:1 (Hebrew: דברים יג, א): "לא תֹסֵף עָלָיו וְלֹא תִגְרַע מִמֶּנּוּ" ("You shall not add to it, nor diminish from it").
  • Devarim 17:11 (Hebrew: דברים יז, יא): "עַל פִּי הַתּוֹרָה אֲשֶׁר יוֹרוּךָ וְעַל הַמִּשְׁפָּט אֲשֶׁר יֹאמְרוּ לְךָ תַּעֲשֶׂה לֹא תָסוּר מִן הַדָּבָר אֲשֶׁר יַגִּידוּ לְךָ יָמִין וּשְׂמֹאל" ("According to the instruction that they instruct you, and according to the judgment that they tell you, you shall do; you shall not turn aside from the word that they declare to you, right or left").

Text Snapshot

The crux of our sugya lies in the concluding methodological statement of the provided text, which clarifies the Rambam's stance on mitzvot d'Rabbanan and Lo Tosif.

"א. אלו תרי"ג מצוות שנמסרו למשה בסיני, עם כלליהן ופרטיהן ודקדוקיהן; וכל אלו הכללות והפרטים והדקדוקים והפירושים של כל מצוה ומצוה היא התורה שבעל פה שנמסרה מדור דור ומבית דין לבית דין." "ב. ויש מצוות אחרות שנתחדשו אחר מתן תורה, אשר תקנום נביאים וחכמים ופשטו בכל ישראל — כקריאת המגילה, ונר חנוכה, ותענית תשעה באב, ונטילת ידים, ועירובין. וכל מצוה ומצוה מאלו יש לה עניינים ודקדוקים משלה; וכל זה יבואר בחבור זה." "ג. וכל אלו המצוות שנתחדשו — אנו חייבים לקבלן ולעשותן, שנאמר: "לא תסור מכל אשר יורוך..." (דברים יז, יא); ואינן תוספת על מצוות התורה. ועל מה הזהירה התורה: "לא תוסיף עליו ולא תגרע ממנו" (דברים יג, א) — זה שאסור לנביא לחדש דבר ולומר שהקב"ה צוה במצוה זו ותיקבע עם מצוות התורה, או לגרוע אחת מתרי"ג מצוות הנזכרות." "ד. אבל אם בית דין עם הנביא שבאותו הדור תיקנו מצוה כתקנה, או כהוראה, או כגזרה — אינה נחשבת תוספת: שהרי לא אמרו שהקב"ה ציום לעשות עירוב או לקרות המגילה בזמנה. שאילו אמרו כן, הרי זה מוסיף על התורה." "ה. אלא שאנו אומרים שהנביאים עם בית דין תיקנו וציוו לקרוא המגילה בזמנה, כדי לזכור שבח הקב"ה, והישועה שעשה לנו, ולקרבנו לעבודתו, ולברכו ולשבחו, ולהודיע לדורות הבאים כי אמת היא הבטחה שהבטיח בתורה, "ומי גוי גדול אשר לו אלהים קרובים אליו" (דברים ד, ז; דברים ד, ח). וכן הוא הדין בכל מצוה ומצוה שהיא מדברי סופרים, בין מצות עשה בין מצות לא תעשה." (Mishneh Torah, Negative Mitzvot 1-365, concluding paragraphs)

Dikduk / Leshon Nuance

The Rambam employs precise terminology:

• "תרי"ג מצוות שנמסרו למשה בסיני" (613 mitzvot delivered to Moses at Sinai) – This clearly defines the d'Oraita corpus as fixed and immutable in its origin.
• "מצוות אחרות שנתחדשו אחר מתן תורה" (other mitzvot that were innovated after the giving of the Torah) – The term "נתחדשו" (innovated/renewed) highlights their post-Sinaitic origin, differentiating them from the fundamental mitzvot.
• "תקנום נביאים וחכמים" (established them by prophets and sages) – Attributes the authority to human agents (prophets and courts), not directly to a new divine revelation.
• "אינן תוספת על מצוות התורה" (they are not an addition to the mitzvot of the Torah) – This is the core claim, directly addressing Lo Tosif.
• "שאסור לנביא לחדש דבר ולומר שהקב"ה צוה במצוה זו ותיקבע עם מצוות התורה" (it is forbidden for a prophet to innovate something and say that the Holy One, blessed be He, commanded this mitzvah and it should be established with the mitzvot of the Torah) – This is the Rambam's narrow interpretation of Lo Tosif. The transgression is specifically in claiming divine authorship for a new mitzvah that joins the 613.
• "תיקנו וציוו לקרוא המגילה בזמנה, כדי לזכור שבח הקב"ה, והישועה שעשה לנו" (established and commanded to read the Megillah at its appointed time, in order to remember the praise of the Holy One, blessed be He, and the salvation He wrought for us) – This provides the teleological justification for mitzvot d'Rabbanan: they serve to enhance existing values (praise of God, remembrance of salvation), not to introduce entirely novel divine demands. They are means to an end, the end being Avodat Hashem as already defined by the Torah.

Readings

Rambam, Sefer HaMitzvot, Shoresh Rishon and Shoresh Sheni

The Rambam's Mishneh Torah statement is a distillation of principles he elaborates at length in the introductions to his Sefer HaMitzvot. In Shoresh Rishon (First Root), he establishes that the count of 613 mitzvot is based only on those explicitly mentioned or clearly implied in the Torah as direct divine commands, transmitted via kabbalah (Oral Tradition). His chiddush here is the rigorous exclusion of mitzvot d'Rabbanan from this count, even while acknowledging their binding nature. He states: "The First Root: That one should not count any Rabbinic commandments, nor any commandments derived through the thirteen exegetical rules, among the 613 commandments." (Rambam, Sefer HaMitzvot, Shoresh Rishon). This sets the stage for our passage, explaining what constitutes the 613, which by definition excludes later enactments.

More pertinently, in Shoresh Sheni (Second Root), the Rambam directly confronts the Lo Tosif issue. His chiddush is his precise definition of Lo Tosif: it forbids only a prophet or a Beit Din from declaring that God Himself commanded an additional mitzvah (or removed an existing one) to be part of the eternal, Sinaitic Torah. However, a Beit Din is empowered by the Torah itself (Lo Tasur, Devarim 17:11) to make fences around the Torah (gezeirot), enact new decrees (takanot), or introduce new customs (minhagim) for the betterment of religious life or to commemorate events. These Rabbinic enactments are not additions to the Torah because they are not presented as min haShamayim (from Heaven) in the same sense as the 613 mitzvot. Rather, they are commanded by the Sages, and the Torah commands us to obey the Sages. Thus, obeying a mitzvah d'Rabbanan is, paradoxically, a fulfillment of a mitzvah d'Oraita – namely, Lo Tasur. The Rambam concludes: "For this reason, when the Sages enacted the reading of the Megillah, or the lighting of Chanukah candles... they did not say 'God commanded us to do this,' but rather 'The Sages commanded us to do this.'" (Rambam, Sefer HaMitzvot, Shoresh Sheni). This directly parallels the concluding paragraphs of the Mishneh Torah text.

Ramban, Hasagot on Sefer HaMitzvot, Shoresh Sheni

The Ramban, in his Hasagot (Critiques) on the Rambam's Sefer HaMitzvot, strongly disagrees with several of the Rambam's Shoreshim, and his critique of Shoresh Sheni is particularly illuminating for our sugya. While he ultimately agrees with the Rambam that mitzvot d'Rabbanan do not violate Lo Tosif, his reasoning is subtly different and highlights a key point of friction.

The Ramban's chiddush is that Lo Tosif is not merely about the attribution of a mitzvah to God, but about the intention behind the act. He argues that if one adds a mitzvah to the Torah with the intention that it is a chova (obligation) from God, even if not claiming new prophecy, that is a transgression of Lo Tosif. However, Rabbinic enactments do not fall into this category because their purpose is not to add to the divine corpus, but to safeguard it or to enhance religious life. They are not considered chovot in the same min haShamayim sense as the 613 mitzvot, even though they are binding. The Ramban writes: "It is clear that the prohibition of Lo Tosif is only on one who adds a mitzvah with the intention that it is from the Torah, that God commanded it... But if the Rabbis establish a fence for the Torah, or a takkanah for the people, it is not considered an addition." (Ramban, Hasagot, Shoresh Sheni).

The Ramban emphasizes that the Rabbis, through their takanot, are not asserting a new divine command, but rather using their authority (granted by Lo Tasur) to legislate for the community. The very fact that the Rabbis distinguish their enactments as d'Rabbanan prevents them from being a tosafah. He also brings the example of the kohanim adding brachot to the Birkat Kohanim in the Temple, which was not considered Lo Tosif, because it was not to "add" to the mitzvah itself, but to enhance its performance. This implies that the spirit of the mitzvah and the intention of the legislator are paramount in defining Lo Tosif.

Friction

The Strongest Kushya

The most potent kushya against the Rambam's distinction is how the introduction of any new religious obligation, particularly one with specific halakhot and even brachot (e.g., lehadlik ner Chanukah), can avoid being an "addition" to the Torah. If the Torah prohibits adding, does it not imply any new religiously binding act? The Gemara itself (e.g., Sanhedrin 88b) recognizes the immense authority of the Sages but also grapples with the tension of Lo Tosif. The Sefer HaChinuch (Mitzvah 454) asks this kushya head-on: "Why are the words of the Sages not considered an addition to the Torah, since they command us to do things that are not written in the Torah, and they even make brachot over them, as if they were mitzvot from the Torah?"

This kushya is particularly sharp when considering Rabbinic mitzvot that carry significant weight, sometimes even more than certain mitzvot d'Oraita (e.g., Chametz on Pesach, where chametz d'Rabbanan is often treated with stringency). If the Sages can institute mitzvot that look, feel, and are enforced much like d'Oraita, how is the semantic game of "they didn't say God commanded it" sufficient to circumvent a clear Biblical prohibition? It feels a bit like a legal fiction, rather than a robust philosophical defense. The Chazon Ish (Orach Chaim 116:4) famously notes that the issur (prohibition) of Lo Tosif is more stringent than any issur d'Rabbanan, yet the Sages establish new issurim. This implies a delicate balance of power and definition.

The Best Terutz (Rambam's Defense)

The Rambam's terutz, as articulated in Sefer HaMitzvot (Shoresh Sheni) and reiterated in the Mishneh Torah conclusion, is multi-faceted and robust:

1. Source of Authority (Lo Tasur): The primary defense is that Rabbinic enactments are themselves a fulfillment of a mitzvah d'Oraita, namely "לא תסור מן הדבר אשר יגידו לך ימין ושמאל" (Devarim 17:11). The Torah explicitly commands us to obey the Sages in all their rulings, interpretations, and enactments. Therefore, when a Beit Din (or prophets and a Beit Din) institutes a takkanah or gezeirah, it is not a new divine mitzvah being added, but rather an application of an existing divine mitzvah (to obey the Sages). In this sense, mitzvot d'Rabbanan are d'Oraita in their binding force, but d'Rabbanan in their origin.

2. Intent and Attribution: The Rambam narrows the scope of Lo Tosif. It does not prohibit any new religious practice or obligation. Rather, it specifically prohibits claiming divine authorship for a new mitzvah and trying to integrate it into the original Sinaitic corpus of 613 mitzvot. The Sages never claim that Chanukah or Purim were commanded directly by God at Sinai or through new prophecy. They explicitly state that these were "תקנום נביאים וחכמים" (established by prophets and sages) to commemorate specific events or to safeguard existing mitzvot. The brachot recited on mitzvot d'Rabbanan (e.g., asher kid'shanu b'mitzvotav v'tzivanu al mikra Megillah) are understood as referring to the divine command to obey the Sages (Lo Tasur), not a direct command for that specific Rabbinic mitzvah.

3. Purpose and Distinction: Rabbinic enactments serve different purposes than the 613 mitzvot. They are often gezeirot (fences around the Torah) to prevent transgression of d'Oraita laws, or takanot (ordinances) to improve society or commemorate significant events, thereby enhancing Avodat Hashem. The Rambam's example for Megillah reading – "כדי לזכור שבח הקב"ה, והישועה שעשה לנו" – highlights this commemorative and pedagogical function. They are not meant to stand as independent, foundational divine commands alongside Shabbat or Kashrut, but as supplementary structures that derive their legitimacy from the Torah's own grant of authority to the Sages.

Intertext

Devarim 17:11: The Foundation of Rabbinic Authority

The Rambam's entire defense hinges on Devarim 17:11: "לֹא תָסוּר מִן הַדָּבָר אֲשֶׁר יַגִּידוּ לְךָ יָמִין וּשְׂמֹאל" ("You shall not turn aside from the word that they declare to you, right or left"). This verse is the bedrock of samchut chachamim (Rabbinic authority). The Gemara in Sanhedrin 88b famously expounds upon this, stating that even if the Sages tell you that right is left and left is right, you must obey, underscoring the absolute nature of their authority in interpretation and legislation. This mitzvah d'Oraita to obey the Sages transforms Rabbinic decrees into a d'Oraita obligation, albeit indirectly. It's the meta-mitzvah that authorizes all other mitzvot d'Rabbanan.

Chagigah 10a: The Weight of Rabbinic Decrees

The Gemara in Chagigah 10a discusses the severity of violating Divrei Sofrim (words of the Scribes/Rabbis). Rabbi Akiva states that one who violates Divrei Sofrim is more deserving of death than one who violates Divrei Torah. While this is an aggadic statement, it powerfully conveys the notion that disrespecting Rabbinic authority, even for seemingly "lesser" laws, can be a more profound spiritual transgression because it undermines the entire system of transmission and interpretation. This reinforces the Rambam's point: mitzvot d'Rabbanan are not merely suggestions; they are serious obligations whose binding power stems from the d'Oraita command of Lo Tasur. The Sages aren't "adding" new divine commands, but rather exercising a divinely granted mandate.

Psak/Practice

The Rambam's delineation of mitzvot d'Oraita and d'Rabbanan forms a cornerstone of halakhic practice and meta-psak heuristics.

1. Severity of Transgression: The distinction directly impacts the severity of punishment. Violations of mitzvot d'Oraita can lead to karet or malkut, whereas violations of mitzvot d'Rabbanan typically incur makat mardut (Rabbinic lashes) or other Rabbinic penalties, rather than the stricter Biblical ones. This is a practical nafka mina in criminal halakha.
2. Doubt (Safek): The rule of safek d'Oraita l'chumra (doubt concerning a Biblical law is resolved stringently) versus safek d'Rabbanan l'kula (doubt concerning a Rabbinic law is resolved leniently) is a fundamental principle of psak. This heuristic is directly dependent on the Rambam's (and other Rishonim's) clear classification of mitzvot.
3. Flexibility and Adaptation: The Rambam's framework allows for the dynamic evolution of halakha. By distinguishing between immutable Sinaitic commands and the Sages' capacity to legislate under Lo Tasur, the system can adapt to new circumstances, commemorate new events, and create "fences" to protect the existing Torah, without ever claiming to alter the divine word itself. This structural flexibility is crucial for the enduring relevance of Jewish law.

Takeaway

The Rambam rigorously defends the legitimacy of Rabbinic enactments by narrowly defining Lo Tosif as a prohibition against claiming divine authorship for new mitzvot. Far from being "additions," mitzvot d'Rabbanan are a dynamic implementation of the d'Oraita command to obey the Sages, ensuring the Torah's continuity and adaptability through the generations.