Numerous halachot are involved in the process of making tefillin. One such halacha is that the letter shin must be etched on both sides of the tefillin shel rosh. Another halacha is that the tefillin shel rosh must have a knot made from the straps that forms the shape of a dalet and the tefillin shel yad must have a knot made from the straps that form the shape of the letter yud.
The Rishonim debate the reason behind these halachot and the halachic weight that they carry. This essay will focus on the dispute between Rashi and Tosafot concerning the nature of the letters formed by the knots and the halachic ramifications that stem from it.
The Gemara in Masechet Menachot states: “And all the nations of the land shall see that the name of the Lord is called upon you, and they shall be afraid of you” (Devarim 28:10); it is taught in a baraita that Rabbi Eliezer the Great says: This is a reference to the tefillin shel rosh.”
The Opinion of Rashi
Rashi explains that the uniqueness of the tefillin shel rosh stems from the fact that it contains the majority of Hashem’s Name Sha–d– ai: The letters shin and dalet (the shin is etched onto the actual tefillin shel rosh bayit, while the dalet is formed by the knot; the letter yud is found on the tefillin shel yad). Hence, there is an added element of kedusha found in the tefillin shel rosh above that of the tefillin shel yad. For this reason, explains Rashi, Rabbi Eliezer attributes the pasuk mentioned specifically to seeing the tefillin shel rosh, as opposed to the tefillin shel yad.
The source for placing these letters on the tefillin can be found in two different sugyot. The Gemara in Shabbat explains that the boxes of tefillin must be made from a kosher animal. The context there is a statement of Rav Yosef that the parchment on which the actual Torah letters are written must be from a kosher animal, based upon the following words (written in the pasuk concerning the mitzva of tefillin), “lema’an tihiyeh Torat Hashem b’ficha,” “so that the Torah of Hashem will be in your mouth”(Shemot 13:9). The Gemara interprets the reference to “your mouth” with regard to the Torah as teaching “min hamutar b’ficha,” that the Torah may only be written on a material that one is permitted to eat. Although this seemingly does not apply to the boxes of tefillin, the Gemara cites Abaye as stating that there is a halacha l’Moshe misinai that the letter shin must be written on the box of the tefillin shel rosh, which the Gemara understands to indicate that the boxes with Torah letters on them must also be made from a kosher animal.
The second sugya, found later in Masechet Shabbat, discusses whether one must remove tefillin when entering a bathroom. There, the Gemara concludes with the statement of Abaye that the shin shel tefillin is a halacha l’Moshe misinai, the dalet shel tefillin is halacha l’Moshe misinai, and the yud shel tefillin is a halacha l’Moshe misinai. Rashi explains (as discussed above) that these three letters are formed with the tefillin. The shin is engraved upon the box of the tefillin shel rosh, the dalet is formed in the knot on the tefillin shel rosh, and the yud is formed on the knot of the tefillin shel yad. Thus, these three letters form Hashem’s name Sha–d–ai, and two of these letters are from the tefillin shel rosh.
The Opinion of Tosafot
From Rashi’s understanding, it would seem that the letters formed by the knots are considered halachically significant (thus creating the higher level of holiness of the shel yad) and would have the same status as other letters written on parchment. Tosafot argue with Rashi and hold that the letters formed by the straps (i.e., the dalet and yud) are not considered halachic letters at all. They prove this from a number of sugyot. Firstly, the fact that the Gemara refers to the tefillin straps as “tashmishei kedusha” and not actual kedusha (which refers to actual Torah words) implies that there are no letters formed by the knots. Furthermore, the Talmud never refers to the knots of the tefillin by anything other than the term “kesher shel tefillin.” If Rashi is correct, then the Gemara should have mentioned that these are also referred to as being actual letters.
Perhaps the strongest proof of Tosafot is their derivation from the first sugya in Shabbat referred to earlier. To recount the sugya briefly, the Gemara cites a ruling of Rav Yosef that “all objects connected to Heaven must be made from kosher hides” and wonders what it refers to. The Gemara initially suggests that Rav Yosef was referring to tefillin and the actual parchment on which the pesukim are written. But the Gemara rejects this, as the need for the parchment to come from a kosher animal is explicitly derived from the derivation of “min hamutar b’ficha,” as mentioned above. The Gemara then proposes that Rav Yosef’s statement refers to the tefillin boxes. But this, too, is rejected as Abaye states that the requirement of a shin is halacha l’Moshe misinai. Finally, the Gemara suggests that perhaps Rav Yosef’s ruling was stated regarding the straps themselves. Tosafot point out that if Rashi is correct, why did the Gemara wait to suggest the straps as the focus of Rav Yosef? Surely, the presence of the dalet and yud should make it obvious that the straps must be made from a kosher animal, just as the Gemara stated earlier regarding the shin. The fact that the Gemara made such a distinction between the shin and the straps proves that the dalet and yud do not have the status of halachic letters at all.
Based on these proofs, Tosafot opine that the version of the Gemara text stating that the dalet and yud are halacha l’moshe misinai is actually incorrect. Rabbeinu Chananel seems to concur with this, as his version of the text also does not state that the dalet and yud are halacha l’moshe misinai.
Tosafot explain that the Gemara in Menachot quoted above that the tefillin shel rosh has a higher status is due to the fact that it is seen by all, as opposed to the tefillin shel yad, which is hidden. He differs on this point from Rashi, who as we saw, explained the difference as a result of the majority of letters of Hashem’s name being present in the tefillin shel rosh.
Practical Ramifications Between Rashi and Tosafot
Seemingly, according to Tosafot, there is no inherent kedusha in the way one ties the straps. Rashi, on the other hand, holds that this is a critical component of the tefillin. Secondly, since Tosafot understand that the elevated status of tefillin shel rosh is due to the fact that they are seen, that means that revealing the tefillin shel rosh is actually a necessity. Rashi, who understands the reason for the elevated status of tefillin shel rosh as being due to the shin and dalet, would not accept this as an obligation, and perhaps holds that it has no value at all.
The Rosh, quoting the Ri of Orleans, mentions a third possible ramification. The Ri of Orleans wonders whether there is an obligation to remove one’s tefillin shel yad when entering a bathroom. According to Tosafot that the knot with the yud is not actually considered a letter, perhaps the obligation to remove tefillin only refers to tefillin shel rosh? Obviously, according to Rashi, there is no question at all, as this would be completely prohibited due to the letter yud on the strap.
The Opinions of Other Rishonim
Rishonim dispute whether the halacha follows Rashi or Tosafot. The Rashba rules that these forms of the dalet and yud do not have the status of actual letters (like Rashi), but he does not go as far as Tosafot and change the text of the Gemara that states that these forms are halacha l’Moshe misinai. Rather, states the Rashba, they are considered a “kesher b’alma,” a mere form of a knot, without the status of letters. But tying them in the form of letters is still considered to be halacha l’Moshe misinai, and it would seem critical that tefillin are tied in this way. The Rosh and Ran also agree with the Rashba that the formation of the letters is necessary but that they are not imparted with the kedusha of actual letters. The Griz suggests that this may be the Rambam’s opinion as well.
The Opinion of the Rambam
The Rambam writes: “There are eight halachot regarding tefillin that are halacha l’Moshe misinai; therefore, they all prevent the fulfillment of the mitzva [if they are lacking], and if one deviated from one of them, he has invalidated the tefillin. They are: That they be square, and be sown… and that on the tefillin shel rosh, there be the shape of a shin, and on the knot, there be the shape of a dalet.
From this halacha, it seems that the Rambam accepts the opinion of Rashi. Yet, in halacha 16, the Rambam writes that only a Jew can make tefillin, since making them is similar to writing them, due to the shin on the leather.” Why did the Rambam not mention the dalet here, as he mentioned beforehand? The Griz explains that according to the Rambam, although the form of the dalet is absolutely necessary as a halacha l’Moshe misinai, it does not have the status of an actual letter. Hence, the Rambam did not include it in halacha 16, which equates fashioning the tefillin with writing the actual words on the parchment.
The Griz proves that the rules of how to tie the straps are clearly halacha l’Moshe misinai, as the Gemara in Eiruvin entertains the possibility that if forming an aniva (a bow) is considered a knot, then one could tie the tefillin in such a manner. The Gemara then rejects this because tefillin is a halacha l’Moshe misinai. The Gemara here is clearly saying that the method of tying the tefillin is a critical component of tefillin, which supports the opinion of the Rambam, Rashi and other Rishonim, against Tosafot.
Furthermore, the Gemara states that Hashem showed Moshe the kesher shel tefillin, a statement that is quoted by the Rif. The Griz asks why the Rif would quote this in his halachic compendium if there were no specific directives about how to tie the tefillin. In fact, Rabbeinu Chananel there explains explicitly that Hashem showed Moshe how to tie the tefillin. The Griz concludes that even Tosafot must agree that the method in which the knots are tied is significant, but only argues that they are not considered letters and perhaps do not have the weight of a halacha l’Moshe misinai. Rav Soloveitchik notes that based on the explanation of the Griz for the Rambam, all of the difficulties of Tosafot against Rashi can be resolved as well.
 Shulchan Aruch, O.C. 32:42
 Shulchan Aruch, O.C. 32:52
 Menachot 35b
 Rashi, ibid. s.v. shem
 Shabbat 28b
 Shabbat 62a
 Rashi, ibid.
 Tosafot, Megilla 26b, s.v. tashmishei kedusha; Tosafot, Menachot 35b s.v. eilu
 Tosafot, Shabbat 62a s.v. shin
 Tosafot, Megilla 26b, s.v. tashmishei kedusha
 Cf. Chiddushei HaGriz, Menachot 35a
 See Shiurei HaGrid, Hilchot Stam, siman 4, where it is noted that the Shulchan Aruch’s ruling that it is proper for the shel rosh to be visible follows Tosafot.
 Rosh, Hilchot Tefillin, siman 12
 Rashba, Shabbat 28a, s.v. nihi d’gemiri
 Rosh, Hilchot Tefillin, siman 12
 Chiddushei HaRan, Shabbat 62a, s.v. v’amar Abaye
 Chiddushei HaGriz, Menachot 35a
 Rambam, Hilchot Tefillin 3:1
 Eiruvin 97a
 Shiurei HaGrid, Hilchot Stam, siman 4