Mishneh Torah, Negative Mitzvot 246-365

Sugya Map

Issue

The core issue elucidated by the Rambam in the concluding lines of this section is the apparent tension between the Torah's prohibition of Lo Tosif U'lo Tigra (Deuteronomy 13:1) – not to add to or diminish from the mitzvos – and the established authority of Chazal to institute Rabbinic ordinances (takkanos, gezeiros, minhagim), which seemingly "add" to the halachic corpus. How can Chazal legislate new mitzvos without transgressing this fundamental negative commandment?

Nafka Mina(s)

• The Nature of Rabbinic Authority: Delineates the source and scope of Chazal's legislative power, distinguishing it from prophetic command.
• Hierarchical Status of Mitzvos: Clarifies the ontological difference between mitzvos d'Oraita (Torah commandments) and mitzvos d'Rabanan (Rabbinic commandments), impacting areas like safek (doubt) and bitul (annulment).
• Criteria for Halachic Innovation: Establishes the conditions under which a Beis Din or prophet may introduce new halachic obligations without violating Lo Tosif.

Primary Sources

• Deuteronomy 13:1 (12:32 in some translations): "Carefully observe everything which I command you to do. Do not add to it and do not diminish from it." (לֹא תֹסֵף עָלָיו וְלֹא תִגְרַע מִמֶּנּוּ).
• Deuteronomy 17:11: "Do not deviate from the instructions that they will give you, left or right." (לֹא תָסוּר מִן הַדָּבָר אֲשֶׁר יַגִּידוּ לְךָ יָמִין וּשְׂמֹאל). This is the mitzvah of Lo Tasur, which forms the basis for Rabbinic authority.
• Examples of Mitzvos d'Rabanan: Megillah, Chanukah candles, Tisha B'Av fast, Netilat Yadayim, Eruvin (as listed by Rambam).

Text Snapshot

The relevant passage begins at the end of the provided text, following the enumeration of the 365 negative commandments.

"These 613 mitzvot were given to Moses on Mount Sinai together with their general principles, particular points, and details. These general principles, particular points, and details represent the Oral Law, which each court received from the previous court. There are [also] other commandments that were instituted after the giving of the Torah. They were established by the Prophets and Sages and spread throughout Israel, for example, the reading of the Megillah, [lighting] a Chanukah candle, fasting on Tish'ah b'Av, [setting up] eruvim, and [washing one's] hands [in preparation for prayer and eating]. Each of these commandments also possesses explanatory aspects and details. All of this will be explained in this text. We are obligated to accept and observe all these commandments which [the Rabbis] instituted, as [implied by Deuteronomy 17:11]: 'Do not deviate from the instructions that they will give you, left or right.' They are not considered to be additions to the commandments of the Torah. [If so,] what was the intention of the Torah's warning (Deuteronomy 13:11): 'Do not add to it and do not detract from it'? That a prophet is not permitted to introduce a new measure and say that the Holy One, blessed be He, commanded this mitzvah to us and that it should be added to the Torah's mitzvot, or [say that He commanded that we] eliminate one of the 613 mitzvot mentioned above. However, if a court, together with the prophet of that age, adds a commandment as an ordinance, a lesson, or as a decree, this is not considered as an addition. He is not saying that the Holy One, blessed be He, commanded us to make an eruv or read the Megillah at its [appointed] time. Were he to say so, he would be adding to the Torah. Instead, we are saying that the prophets and the courts ordained and commanded that the Megillah be read at its [appointed] time in order to recall the praise of the Holy One, blessed be He, the salvation He wrought for us, and His response to our cries, so that we will bless Him, extol Him, and inform the future generations of the truth of the Torah's promise (Deuteronomy 4:7): 'What nation is so great that it has God [close to it....]". Similar principles apply with regard to all the other Rabbinic commandments, be they positive commandments or negative commandments."¹Mishneh Torah, Negative Mitzvot 365.

Dikduk/Leshon Nuance

The Rambam’s precise language is key. He initially states, "They are not considered to be additions to the commandments of the Torah." This immediately flags the kushya of Lo Tosif. His subsequent explanation clarifies that the prohibition of Lo Tosif applies specifically to claiming divine origin for a new mitzvah ("...and say that the Holy One, blessed be He, commanded this mitzvah to us..."). Conversely, Chazal's enactments are permissible because they are presented as human legislation by the Beis Din and prophets, albeit binding due to the Torah's command of Lo Tasur ("...the prophets and the courts ordained and commanded..."). The distinction lies in the attribution of authority – human vs. divine. The phrase "וְלֹא הִכְוִינוּ בּוֹ אֶלָּא לְהַזְכִּיר שֶׁהַקָּדוֹשׁ בָּרוּךְ הוּא צִוָּה אוֹתָנוּ לַעֲשׂוֹת עֵרוּב אוֹ לִקְרוֹת מְגִלָּה בִּזְמַנָּהּ" (my translation: "And we did not intend with it but to recall that the Holy One, blessed be He, commanded us to make an eruv or read the Megillah in its time") effectively means, "They did not claim God commanded us to make an eruv or read the Megillah..." emphasizing that had they claimed it, it would be Lo Tosif. The Sefaria translation "He is not saying..." captures this well.

Readings

Rambam, Sefer HaMitzvot, Shoresh Rishon

The Rambam systematically lays out his fourteen principles for counting the 613 mitzvos in Sefer HaMitzvot. His very first principle (Shoresh Rishon) is foundational to understanding the passage at hand. He states unequivocally that only commandments derived directly from the Torah, whether explicitly stated or through drashos that are halacha l'Moshe miSinai, are counted among the 613.²Sefer HaMitzvot, Shoresh Rishon. Mitzvos d'Rabanan, while binding, are explicitly excluded.

His chiddush here is the categorical distinction between divrei Torah and divrei Sofrim. Lo Tosif is understood as a safeguard against blurring this distinction. If Chazal were to claim that their enactments were divrei Hashem in the same sense as the Torah Sheb'al Peh (Oral Torah) received by Moshe at Sinai, it would be a direct violation of Lo Tosif. However, when they legislate, they do so based on the authority granted to them by the Torah itself, through the mitzvah of Lo Tasur (Deuteronomy 17:11), which obligates us to obey the rulings of the Sanhedrin.³Mishneh Torah, Hilchot Mamrim 1:2. Thus, their enactments are not additions to the Torah in the prohibited sense, but rather extensions or fences (seyagim) around it, or new mitzvos whose obligation is d'Oraita (from Lo Tasur), but whose content is d'Rabanan.

Sefer HaChinuch, Mitzvah 454 (Lo Tosif)

The Sefer HaChinuch, attributed to Rav Aharon HaLevi (Ra'ah) or a student, generally follows the Rambam's enumeration and understanding of the mitzvos. In his explanation of Mitzvah 454, the prohibition of Lo Tosif, he reiterates the Rambam's fundamental point. The Chinuch explains that the purpose of Lo Tosif is to preserve the integrity and divine origin of the Torah.⁴Sefer HaChinuch, Mitzvah 454. Any attempt to add a mitzvah and attribute it to God undermines the perfection and completeness of His divine law.

His chiddush lies in emphasizing the intent of the addition. It is not merely the act of performing an extra mitzvah that constitutes Lo Tosif, but the belief and assertion that this extra mitzvah was commanded by God and belongs to the original divine corpus of mitzvos. If one were to add an extra tzitzit string or an extra species to the Lulav with the intention that Hashem commanded this, it would be Lo Tosif. However, if one does so as a chumra (stringency) or minhag (custom) without claiming divine command, it is not a violation. Chazal's enactments fall into this latter category; they are introduced as Rabbinic enactments, fulfilling the Torah's command of Lo Tasur, rather than being presented as new divine commands.

Minchas Chinuch, Mitzvah 454

The Minchas Chinuch, Rabbi Yosef Babad's commentary on the Sefer HaChinuch, delves deeper into the halachic nuances of Lo Tosif. He elaborates on the Rambam's distinction, highlighting the practical nafka minos.

The Minchas Chinuch clarifies that the prohibition of Lo Tosif is not against adding actions per se, but against adding commands to the Torah's system as if they were d'Oraita.⁵Minchas Chinuch, Mitzvah 454, s.v. "U'v'Sefer HaMitzvot". He discusses scenarios where one might perform an act akin to a mitzvah (e.g., taking an extra Lulav) purely as a chumra or out of love for mitzvos, and how this differs from Lo Tosif. The chiddush here is in the exploration of the metaphysical aspect of mitzvah performance. An act performed without the halachic kavana (intention) of fulfilling a divine mitzvah is not necessarily problematic. Rabbinic mitzvos are understood as distinct entities; their performance fulfills a Rabbinic command, which is itself rooted in the Torah command of Lo Tasur. The Minchas Chinuch might further explore whether one can violate Lo Tosif through shev v'al ta'aseh (inaction) by not performing a mitzvah d'Oraita as commanded while claiming to do so based on a "new" divine instruction.

Friction

The Strongest Kushya

The primary kushya against the Rambam's explanation is that, regardless of the attribution, Chazal's enactments demonstrably add to the sum total of halachic obligations placed upon a Jew. When the Torah states, "Do not add to it," it does not explicitly differentiate between adding as if from God and adding as from the Sages. From the perspective of the average Jew, the halachic burden is increased, and new mitzvos are introduced. For instance, lighting Chanukah candles or reciting Hallel on Rosh Chodesh (a Minhag) are new mitzvos that were not part of the original 613 given at Sinai. Even if the authority to create them is d'Oraita (from Lo Tasur), the content is a new obligation. Isn't this, in essence, an "addition" to the Torah's commandments, violating the plain sense of Lo Tosif? Some might argue that the very act of declaring a new mitzvah as obligatory, even if Rabbinic, constitutes an addition to the corpus of halacha, which Lo Tosif aims to preserve in its original, divinely ordained form. The Yerushalmi Sanhedrin 4:2⁶Yerushalmi Sanhedrin 4:2, 22a. discusses the authority of Beis Din and hints at the careful balance needed to avoid Lo Tosif.

The Best Terutz

The Rambam's terutz, articulated in the text and elaborated in Sefer HaMitzvot and Hilchot Mamrim, is multi-faceted and robust.

1. Distinction in Authority and Claim: The prohibition of Lo Tosif applies only when one claims that a new mitzvah was divinely commanded and is an integral part of the original 613 mitzvos of the Torah. This would imply that the Torah was incomplete or flawed, requiring supplementation from God. Chazal, however, never make such a claim. They explicitly state that their enactments are m'divreihem (from their words/authority), not m'pi HaGevurah (from the mouth of God).
2. Foundation in Lo Tasur: The obligation to observe Rabbinic enactments is itself a mitzvah d'Oraita, derived from "Do not deviate from the instructions that they will give you" (Deuteronomy 17:11).⁷Mishneh Torah, Hilchot Mamrim 1:1. Thus, obeying Chazal is fulfilling a Torah command, not adding to it. The content of the Rabbinic mitzvah (e.g., lighting Chanukah candles) is distinct from the obligation to perform it (which is d'Oraita).
3. Nature of Rabbinic Enactments: Chazal's enactments typically serve one of three purposes:
   • Seyag l'Torah: A "fence" or protective measure around a Torah mitzvah to prevent its transgression (e.g., muktzah to protect Shabbat).
   • Takkanah: An ordinance enacted to improve religious life or address changing circumstances (e.g., Eruv to facilitate Shabbat observance in specific domains).
   • Gezeirah: A decree prohibiting something that is d'Oraita permissible, usually to prevent a more severe d'Oraita transgression (e.g., prohibition of bishul akum).
   • Minhag: A custom that becomes binding. None of these are presented as new divine commands, but as Beis Din's application of their Torah-granted authority to ensure the continued observance and vitality of the Torah. The Rambam's terutz focuses on the source and type of command, not just the resulting action. It is an "addition" to our practice, but not an "addition" to the divine Torah itself.

Intertext

Sifre Devarim 13:1 (Piska 85)

The Sifre on Devarim 13:1 (which is 12:32 in some chapter divisions) directly addresses the prohibition of Lo Tosif. It states:

"לא תוסף עליו - שתאמר מצוה זו ציווה הקב"ה לעשותה, כגון חמש פרשיות בתפילין, או חמש מינים בלולב, והכל לשם שמים."⁸Sifre Devarim, Piska 85, s.v. "Lo Tosif Alav". (Do not add to it – that you should say, "This mitzvah the Holy One, Blessed be He, commanded to do," for example, five sections in tefillin, or five species in a lulav, even if it is all for the sake of Heaven.)

This classical Midrash Halacha provides the foundational understanding for the Rambam's position. It explicitly identifies the violation of Lo Tosif not merely with performing an extra act, but with the claim that God commanded it. The examples given – adding to the number of parshiyot in tefillin or species in the lulav – are specific instances where one would be altering the divine prescription and attributing that alteration to God. This text perfectly aligns with the Rambam's explanation that Chazal's enactments are not Lo Tosif because they are never presented as divine additions to the original mitzvos, but as human legislation authorized by the Torah itself.

Maseches Sanhedrin 88b (on Lo Tasur)

The Gemara in Sanhedrin 88b discusses the mitzvah of Lo Tasur (Deuteronomy 17:11), the source for the authority of the Sanhedrin to legislate. The Gemara states:

"אפילו אומרים לך על ימין שהוא שמאל ועל שמאל שהוא ימין – שמע להם."⁹Sanhedrin 88b. (Even if they tell you concerning right that it is left, and concerning left that it is right – listen to them.)

This hyperbolic statement underscores the immense authority granted to the Sanhedrin and, by extension, to subsequent Chazal in interpreting and applying halacha. The intertextual connection is crucial: Lo Tosif limits who can add (only God) and how they can add (not by falsely attributing it to God). Lo Tasur, conversely, establishes the obligation to follow the interpretations and enactments of the authorized halachic body. These two mitzvos work in tandem to define the boundaries of Torah Sheb'al Peh. Lo Tosif ensures the divine integrity of the Torah as given at Sinai, while Lo Tasur ensures the ongoing, dynamic application and development of halacha through the generations, based on the authority invested in Chazal. The Gemara's emphasis on obedience to Chazal demonstrates that their authority is divinely sanctioned, making their enactments binding without violating the spirit or letter of Lo Tosif.

Psak/Practice

The Rambam's analysis of Lo Tosif and mitzvos d'Rabanan is fundamental to halachic psak and meta-psak heuristics.

Halachic Practice

1. Distinction in Severity: Rabbinic prohibitions, while fully binding, are generally less severe than d'Oraita prohibitions. This manifests in rules like safek d'Oraita l'chumra (doubt in Torah law is stringent) versus safek d'Rabanan l'kula (doubt in Rabbinic law is lenient). For instance, if there is a doubt whether chametz is present on Pesach (d'Oraita), we are stringent; if there is a doubt regarding a Rabbinic prohibition, we are often lenient.
2. Annulment of Decrees: A later Beis Din may have the authority to annul a decree made by an earlier Beis Din, provided the later court is greater in wisdom and number, or if the decree was not accepted by the majority of Israel.¹⁰Mishneh Torah, Hilchot Mamrim 2:2. This is only possible for Rabbinic decrees; Torah mitzvos are immutable.
3. No New D'Oraita Mitzvos: The psak is clear that no individual or Beis Din, even a prophet, can introduce a new mitzvah and claim it to be d'Oraita. Any such claim would be a violation of Lo Tosif.

Meta-Psak Heuristics

The Rambam provides the intellectual framework for understanding the dynamic nature of halacha. The Torah is not a static document but a living system, constantly interpreted and applied by Chazal. The Lo Tosif limitation ensures fidelity to the divine origin, while Lo Tasur empowers Chazal to adapt and build upon that foundation. This heuristic underscores that halacha is not merely a collection of rules, but a system whose development is itself divinely sanctioned and constrained. It also highlights the importance of mesorah (tradition) in identifying which mitzvos are d'Oraita and which are d'Rabanan, as the distinction in origin is crucial.

Takeaway

The Rambam masterfully resolves the apparent contradiction between Lo Tosif and Rabbinic enactments by distinguishing between divine command and human legislation, both binding through the Torah's own mandate of Lo Tasur. This framework preserves the immutable integrity of the 613 mitzvos while allowing for dynamic halachic development and practical application by Chazal throughout the generations.

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1. Mishneh Torah, Negative Mitzvot 365.
2. Sefer HaMitzvot, Shoresh Rishon.
3. Mishneh Torah, Hilchot Mamrim 1:2.
4. Sefer HaChinuch, Mitzvah 454.
5. Minchas Chinuch, Mitzvah 454, s.v. "U'v'Sefer HaMitzvot".
6. Yerushalmi Sanhedrin 4:2, 22a.
7. Mishneh Torah, Hilchot Mamrim 1:1.
8. Sifre Devarim, Piska 85, s.v. "Lo Tosif Alav".
9. Sanhedrin 88b.
10. Mishneh Torah, Hilchot Mamrim 2:2.