Menachot 37

Sugya Map

The sugya on Menachot 37a grapples with the precise placement of the Tefillin shel Yad (arm phylactery), specifically on which arm and where on that arm.

• Issue: Determining which arm is designated for Tefillin shel Yad and the exact location on that arm.
• Nafka Mina(s):
  • The halakha for right-handed individuals.
  • The halakha for left-handed individuals (iṭṭer).
  • The halakha for ambidextrous individuals (sholeṭ bi-shtei yadav).
  • The exact anatomical placement on the arm (bicep vs. hand).
  • Whether the tefillin must be covered.
• Primary Sources:
  • Genesis 48:17 ("yad yemino")
  • Deuteronomy 6:8 ("u-k’shartam l’ot al yadekha") & 6:9 ("u-kh’tavtam al mezuzot beitekha")
  • Exodus 13:16 ("yadkha" written with a heh)
  • Deuteronomy 11:18 ("u-k’shartam l’ot al yedkhem")
  • Exodus 13:9 ("l’ot lekha al yadekha")
  • Deuteronomy 14:1 ("lo titgod’du v’lo tasimu korḥa bein eineikhem l’met")
  • Leviticus 13:29-37 (laws of nega'im on the head/beard).

Text Snapshot

The Gemara presents several derivations for the placement of Tefillin shel Yad.

• Rabbi Yosei HaChorem (37a): "מצינו ימין שנקרא יד, שנאמר: 'וירא יוסף כי ישית אביו יד ימינו' (בראשית מח, יז)."^1(#f1) — "We have found that the right hand is also called yad, as it is stated: 'And when Joseph saw that his father was laying his right hand [yad yemino]'" (Genesis 48:17). This Tanna argues that "yad" can refer to the right hand, challenging a Baraita's assumption that yad (unspecified) refers only to the left. The opposing Tanna responds: "yad yemino איקרי, אבל yad סתמא לא איקרי."^2(#f2) — "It is called 'his right hand,' but it is not called a yad without further specification." This is a crucial dikduk on the specificity of the term "yad."

• Rabbi Natan (37a): "מה כתיבה בימין, אף קשירה בימין; וכיון דקשירה בימין, הנחה בשמאל היא."^3(#f3) — "Just as writing is with the right hand... so too, the binding [of phylacteries] must be performed with the right hand. And since binding is with the right hand, this means that donning is on the left arm." This derivation hinges on the proximity of "וקשרתם" (Deut. 6:8) and "וכתבתם" (Deut. 6:9) and the sevara that one binds with their dominant hand.

• Rav Ashi (37a): "מ"ידכה" דכתיב ה"י, כהה."^4(#f4) — "From the verse 'your arm [yadkha]' (Exodus 13:16), which is written with a letter heh [at the end], [it is expounded as though it stated]: your weak [keha] arm." This is a drasha on the final heh of yadkha, taking it to mean "weak" (כהה), thus mandating the weaker arm. Rabbi Abba challenges this, suggesting it could be yadko'ach (ידכוח) meaning "arm of strength," but Rav Ashi refutes this by pointing out the actual spelling: "ה"י כתיב?!"^5(#f5) — "Is it written with a ḥet?!" This highlights the importance of masora in scriptural spelling for drashot.

Readings

Rashi's Elucidation of the "Weak Arm" Principle

Rashi, ever the pashṭan yet deeply rooted in midrash, provides crucial context for understanding the various derivations. On Rabbi Yosei HaChorem's statement, Rashi clarifies that "מצינו ימין שנקרא יד — ולא ילפינן מהכא"^6(#f6) — "We find that the right hand is called yad — but we do not derive from here." This is key: Rabbi Yosei is challenging a premise, not offering his own derivation for the left arm. He's saying, "If you thought yad means left by default, here's a counterexample." The halakha that it's on the left still needs a source, which the Gemara later provides.

Regarding Rabbi Natan's derivation, Rashi explains the logical flow: "מה (מזוזה) כתיבה בימין — כשכותבין המזוזה בימין דרוב בני אדם כותבין בימין אף קשירה נמי עבד קשר בימין ומדקשר בימין מכלל הנחה בשמאל דאי הנחה על ימין שוב אינו יכול לקושרה בימין."^7(#f7) — "Just as writing [mezuzah] is with the right hand — since most people write with their right hand, so too the tying [of tefillin] is done with the right hand. And since one ties with the right hand, it implies placement on the left, for if it were placed on the right, he could not tie it with his right hand." Rashi emphasizes the rov (majority) of people being right-handed for the k'tiva analogy. This sevara (reasoning) of needing a free dominant hand to tie on the non-dominant arm becomes a foundational understanding for R' Natan's approach.

On Rav Ashi's drasha of yadkha as keha (weak), Rashi succinctly points to the masora of the written text. This drasha provides an independent, textual basis for the "weaker arm" principle, which is critical given the nafka mina for left-handed people.

Tosafot's Nuances and Challenges

Tosafot, with their characteristic dialectical approach, delve deeper into the sugya's implications. On Rabbi Yosei HaChorem's name, Tosafot (citing "מ"ר") challenge Rashi's explanation that "HaChorem" refers to a sunken nose, calling it "ותימה הוא לומר שכינהו בלשון גנאי אלא על שם מקומו נקרא כן."^8(#f8) — "It is puzzling to say that he was called by a derogatory term; rather, he was named after his place." This small note highlights Tosafot's sensitivity to the kavod ha-Torah and the Sages.

More substantively, regarding Rabbi Yosei's proof from yad yemino, Tosafot ask why he didn't bring a proof from "yado hayemanit d'metzora" (the right hand of a leper)^9(#f9). They explain that Rabbi Yosei too relies on the verse yad yemino, and since it already specifies "right," it's not a generic "yad." This subtle point reinforces the idea that yad saṭma (unspecified yad) does not refer to the right.

Crucially, Tosafot connect Rabbi Natan's sevara of "what writing is with the right, so too tying with the right" to the later discussion of left-handed people. They ask: "בסמוך אמרי' דאיטר מניח תפילין בימינו שהיא שמאלו והשתא אדם הכותב בימינו ושאר רוב מעשיו בשמאלו יש להסתפק באיזה מהן מניח תפילין ושמא יש לדמותו כשולט בשתי ידיו."^10(#f10) — "Nearby, we say that a left-handed person dons tefillin on his right arm, which is his left [i.e., weaker]. Now, a person who writes with his right hand but performs most other actions with his left, there is a doubt on which [arm] he dons tefillin. Perhaps he should be likened to one who is ambidextrous." This is a brilliant nafka mina that directly challenges the simplicity of Rabbi Natan's "writing with the right" rule. If "writing" defines the dominant hand, what about someone whose dominant hand for most tasks is different from their writing hand? This pushes the inquiry from a simple "right vs. left" to a deeper principle of "dominant vs. non-dominant" or "strong vs. weak."

Steinsaltz's Synthesized Overview

Rabbi Adin Steinsaltz's commentary offers a clear, consolidated view of the initial arguments. He translates and summarizes the core positions, making the sugya's rapid-fire arguments accessible. For instance, he clearly articulates the distinction between "yad" and "yad yemino": "יד ימינו איקרי [נקרא], אבל יד סתמא [סתם] לא איקרי [לא נקרא]."^11(#f11) This succinct explanation captures the linguistic precision the Gemara demands. Steinsaltz also lays out Rabbi Natan's argument, reiterating how the k'tiva (writing) analogy leads to k'shira (tying) with the right and hanaḥa (placement) on the left, because "שאינו יכול לקשור את התפילין ביד שעליה הוא מניח אותן."^12(#f12) — "he cannot tie the tefillin on the hand upon which he is donning them." Steinsaltz thus serves to clarify the p'shat before the deeper lomdus of Tosafot and the halakhic implications.

Friction

The Confluence of Derivations and the "Weaker Arm" Principle

The most significant friction point in this sugya arises from the tension between the various derivations for Tefillin shel Yad placement and their application to individuals with non-standard handedness.

The Kushya: Rabbi Natan's derivation, "מה כתיבה בימין, אף קשירה בימין; וכיון דקשירה בימין, הנחה בשמאל היא,"^13(#f13) establishes a clear link between the dominant hand (for writing) and the act of tying, leading to placement on the left. This sevara seems to root the halakha in the status quo of a right-handed majority. However, the Gemara immediately introduces the drasha of Rav Ashi, "מ"ידכה" דכתיב ה"י, כהה,"^14(#f14) interpreting yadkha as the "weak arm." This textual derivation independently points to the weaker arm.

The friction intensifies when the Gemara discusses the halakha for an iṭṭer (left-handed person). The baraita states: "איטר מניח תפילין בימינו שהיא שמאלו."^15(#f15) — "A left-handed person dons tefillin on his right arm, which is his left arm." This means they place tefillin on their non-dominant arm, which for them is the right. If Rabbi Natan's logic—based on tying with the dominant hand (the right for most people) and thus placing on the left—were universally applied, a left-handed person, whose dominant hand is the left, should tie with their left and place on their right. While the result for the iṭṭer (placement on the right) is consistent with the baraita, the reasoning is flipped. Rabbi Natan's midrash relies on the general dominance of the right hand for writing, whereas the baraita explicitly dictates placement based on the individual's weaker arm.

Furthermore, the Gemara asks Rabbi Yosei HaChorem, who allows yad to refer to the right, how he derives placement on the left. The answer: "נפקא ליה מהיכא דנפקא ליה לר' נתן."^16(#f16) — "He derives it from where Rabbi Natan derives it." This implies a shared underlying mesorah or sevara even if the initial textual arguments differ. How can they share a mesorah if one is based on a "right-handed world" and the other on a "weak arm" principle?

The Terutz: The various derivations, while seemingly distinct, converge on a single underlying principle: the Tefillin shel Yad is placed on the non-dominant arm.

1. Reconciling Rabbi Natan with the "Weak Arm": Rabbi Natan's midrash from "writing" (Deut. 6:8-9) identifies the dominant hand as the one used for tying, leading to placement on the other. For the rov (majority) of people who are right-handed, this means tying with the right and placing on the left. The Gemara's answer that Rabbi Yosei HaChorem also derives from Rabbi Natan's source suggests that the drasha "מה כתיבה בימין, אף קשירה בימין" is not merely about which hand writes, but rather about the principle of using the dominant hand to tie on the non-dominant.
2. Rav Ashi's Drasha as the Underlying Principle: Rav Ashi's drasha of yadkha (Exodus 13:16) as keha (weak) provides a direct, explicit textual basis for the "weaker arm" principle. This drasha is individual-centric. The dispute between tanna'im on yadkha (weak arm vs. including one without a complete arm) further solidifies the notion that yadkha is the source for the type of arm, not just its laterality.
3. The Baraita as the Decisive Halakha: The baraita regarding the iṭṭer — "איטר מניח תפילין בימינו שהיא שמאלו" — serves as the definitive halakha, establishing that the principle is indeed the weaker/non-dominant arm, irrespective of whether that arm is anatomically "left" or "right." The phrase "שהיא שמאלו" clarifies that his right arm functions as his weaker arm.

Thus, the terutz is that all these derivations, though coming from different angles (linguistic nuance, contextual midrash, explicit drasha), ultimately point to the same halakhic conclusion: Tefillin shel Yad are placed on the non-dominant, weaker arm. Rabbi Natan's midrash is a sevara that applies to the majority, while Rav Ashi's drasha and the baraita on the iṭṭer reveal the universal underlying principle. The halakha for an ambidextrous person (sholeṭ bi-shtei yadav), who places on the left, as explained by Abaye^17(#f17), is consistent: even if both are strong, the anatomical left is the default for rov amolakhah.

Intertext

The emphasis on the "weaker arm" (yad keha) or "non-dominant arm" for Tefillin shel Yad is a unique halakhic principle that guides the performance of this mitzvah. While other mitzvot specify "right" or "left" for symbolic or practical reasons, the Tefillin shel Yad is determined by individual physiology.

1. Contrast with Yamin in Other Mitzvot: Many mitzvot explicitly mention the "right hand" or "right side" as preferable or required, often signifying importance, strength, or honor. For instance, the Kohen Gadol's semicha (laying on of hands) on the metzora involves placing blood and oil on the t'nul yad yemin (lobe of the right ear), bohen yad yemin (thumb of the right hand), and bohen regel yemin (big toe of the right foot) (Leviticus 14:14, 17, 25, 28). Similarly, the Kohen Gadol receives the blood of the par he'alem davar on his right thumb and big toe (Leviticus 4:25). These instances highlight the yamin as the primary or more significant limb. The Tefillin shel Yad, in contrast, explicitly seeks the keha (weak) arm. This inversion underscores the specific purpose of Tefillin as a "sign upon your arm" (Exodus 13:16) — it is perhaps meant to be a constant reminder, not necessarily an act of strength or honor in its placement, but rather a connection to the heart (as per R' Yitzchak's derivation, Menachot 37a^18(#f18): "מקום הנחה כנגד הלב").
2. Shulchan Aruch on Iṭṭer: The halakha for the iṭṭer (left-handed person) is directly codified in the Shulchan Aruch, Orach Chaim 27:2. "איטר מניח תפילין בימינו, שהיא שמאלו. ואיטר רגיל בשתי ידיו מניח בשמאלו."^19(#f19) — "A left-handed person dons tefillin on his right arm, which is his left [i.e., weaker]. And an ambidextrous person dons on his left." This psak directly reflects the discussion in Menachot 37a. The determining factor is "שמאלו" (his weaker arm), rather than the anatomical "left." For one who is ambidextrous (sholeṭ bi-shtei yadav), the Shulchan Aruch follows Abaye's ruling in the Gemara, that he places on his anatomical left. This implies that if there's no clear "weaker" arm, the default anatomical left is used, perhaps reflecting the rov understanding of yadkha or a gezeirat ha-katuv.

Psak/Practice

The halakha l'ma'aseh (practical ruling) for Tefillin shel Yad is firmly established based on the Gemara's discussion.

1. Right-Handed Individuals: A right-handed person, whose left arm is their weaker/non-dominant arm, dons Tefillin shel Yad on their left arm.^20(#f20) The k'tzitzah (cube-shaped base) should rest on the bicep, aligned with the heart, and the straps are wound seven times around the forearm and three times around the middle finger.
2. Left-Handed Individuals (Iṭṭer): An iṭṭer, whose right arm is their weaker/non-dominant arm, dons Tefillin shel Yad on their right arm.^21(#f21) The principle is the "weaker arm" (or the arm not used for primary tasks). This is often defined as the arm they do not use for writing or for the majority of their strenuous activities.
3. Ambidextrous Individuals (Sholeṭ Bi-Shtei Yadav): An individual who is equally proficient with both hands dons Tefillin shel Yad on their left arm.^22(#f22) This follows Abaye's explanation in the Gemara. The Rema adds a stringency for such an individual to don tefillin on both arms, without bracha on the second, but the prevalent custom is to rely on the opinion that the anatomical left is sufficient.^23(#f23)
4. Placement on the Arm: The Tefillin shel Yad is placed on the bicep ("בזרוע"), specifically the upper part, "כנגד הלב" (opposite the heart).^24(#f24) This is derived from the drasha of R' Yitzchak ("Therefore you shall place these words in your heart... and you shall bind them") and the hekesh (analogy) to tefillin shel rosh ("just as there [on the head], it is on the upper part, so too here [on the arm], it is on the upper part").^25(#f25)
5. Visibility: While Rabbi Eliezer suggests "a sign for you, but not a sign for others" (Exodus 13:9), implying the tefillin should be covered, Ameimar clarifies that this refers to the place being one generally covered (the bicep), not that the tefillin must always be hidden. Thus, if a sleeve tears, it is not an issue, though custom is to keep them covered.^26(#f26)

Takeaway

The sugya masterfully weaves together linguistic analysis, contextual midrash, and explicit drasha to establish that Tefillin shel Yad are donned on the weaker/non-dominant arm, a principle that transcends anatomical laterality and grounds the mitzvah in individual physiology. The rigorous debate ultimately converges on the pragmatic and textual imperative of yad keha, ensuring the tefillin serve as a personal sign "upon your arm" in the most fitting manner for each individual.

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Footnotes:

1. Menachot 37a.
2. Menachot 37a.
3. Menachot 37a.
4. Menachot 37a.
5. Menachot 37a.
6. Rashi, Menachot 37a s.v. "מצינו ימין שנקרא יד".
7. Rashi, Menachot 37a s.v. "מה כתיבה בימין".
8. Tosafot, Menachot 37a s.v. "רבי יוסי החורם".
9. Tosafot, Menachot 37a s.v. "יד ימינו איקרי".
10. Tosafot, Menachot 37a s.v. "מה כתיבה בימין אף קשירה בימין".
11. Steinsaltz, Menachot 37a.
12. Steinsaltz, Menachot 37a.
13. Menachot 37a.
14. Menachot 37a.
15. Menachot 37a.
16. Menachot 37a.
17. Menachot 37a.
18. Menachot 37a.
19. Shulchan Aruch, Orach Chaim 27:2.
20. Shulchan Aruch, Orach Chaim 27:2.
21. Shulchan Aruch, Orach Chaim 27:2.
22. Shulchan Aruch, Orach Chaim 27:2.
23. Rema, Orach Chaim 27:2.
24. Menachot 37a; Shulchan Aruch, Orach Chaim 27:8.
25. Menachot 37a.
26. Menachot 37a; Shulchan Aruch, Orach Chaim 27:12.