1) THE "TOP KNOT" OF THE TZITZIS
OPINIONS: The Gemara says that the top knot of the Tzitzis, where the Tzitzis is attached to the garment, is a Torah requirement. This is evident from the fact that the Torah teaches -- through the proximity of the verse of the Mitzvah of Tzitzis to the verse of the Isur of Sha'atnez -- that Tzitzis may be made from Sha'atnez. If a knot was not necessary mid'Oraisa, then the Torah would not have to teach that Tzitzis may be made from Sha'atnez, since the Tzitzis could be made merely by placing the strings of Techeles (which are wool) into the garment (made of linen) without tying them. The Isur of Sha'atnez would not apply since the mixture of wool and linen is prohibited only when the wool and linen are bonded or tied together into a single entity. It must be that the Torah requires that the Tzitzis be tied with a knot to the garment, and thus it is also necessary for the Torah to teach that the Mitzvah of Tzitzis overrides the Isur of Sha'atnez.
To which knot does the Gemara refer when it says that the "top knot" is required mid'Oraisa?
(a) RASHI (DH Kesher Elyon) explains that the "top knot" refers to the knot at the end of the wound strings. That is, after the strings are wound, a knot is tied. That knot is mid'Oraisa. Rashi explains that the reason why this knot is called the "top knot" is that a person can wind a string around other strings and keep the strings in place by making a knot at the end of the wound strings. On the other hand, a knot made before winding the strings would not hold the "Gedil" (wound strings) in place. It is logical that the Torah requires a knot that holds the wound strings in place.
However, although the importance of this knot at the end of the wound strings is clear, it still is not clear why the Gemara refers to this knot as the "top" knot, which implies the knot that is closest to the garment. Why is the knot at the end of the wound strings called the "top" knot?
1. TOSFOS (DH Kesher ha'Elyon) cites a precedent for this terminology from the Gemara in Nidah (13b) which says "from the Atarah and 'l'Ma'alah,'" which means away from the Atarah, towards the body, and not towards the top of the Atarah.
2. The SHITAH MEKUBETZES (38b, #6) explains that this knot is called the "top knot" because when a person lifts the Tzitzis in his hand (to kiss it or to look at it), this is the knot which is at the "top." (See the MORDECHAI for a third explanation.)
(b) TOSFOS quotes another explanation in the name of Rashi, which does not appear in our text of Rashi (however, it does appear in Rashi in Sanhedrin 88b, DH Kesher Elyon). This explanation states that the "top knot" indeed is the knot closest to the garment to which the Tzitzis are attached. As mentioned above, the source that the top knot is required mid'Oraisa is the fact that the Torah teaches that the Mitzvah of Tzitzis overrides the Isur of Sha'atnez. If the Torah would be referring to the knot after the wound strings, the Torah would not need to teach that Sha'atnez is permitted, because the Tzitzis would not involve Sha'atnez at all; a knot after the wound strings would not make the woolen strings a single entity with the linen garment, since the knot is so far removed from the garment.
REBBI SHMUEL SHMELKA TOIVESH points out that, according to the first explanation, the knot does not have to be present at the very end of the wound strings. Even if the knot is preceded by a few wound strings, this knot suffices. However, according to the second explanation, in order for the Torah to need to teach that Sha'atnez is permitted in Tzitzis, it must be that the Torah requires a knot right next to the garment.
(c) The CHIDUSHEI HA'RAN in Sanhedrin (88b) quotes RABEINU DAVID who gives a third explanation. He understands that, in order to derive that the knot next to the garment is a Torah requirement, the Torah does not need to teach that Sha'atnez is permitted in Tzitzis. The Gemara's teaching pertains to the top knot after the wound strings, and the Gemara concludes that this knot is also a Torah requirement. Although there is also one knot next to the garment, this is still not enough to consider the Tzitzis connected to the garment, since two knots are required to make it bonded to the garment. The fact that the verse needs to teach that Sha'atnez is permitted in Tzitzis shows that there must be two knots according to Torah law, one on each side of the wound strings.
The Chidushei ha'Ran argues with this explanation for a number of reasons. One reason is that according to Rabeinu David, who explains that the knot at the beginning is a single knot, and the knot at the end is a single knot (contrary to our custom of tying double knots in each place), when the Gemara says, "Tekifah Achas Eino Chibur" -- "one 'attachment' is not considered a connection," it means that one knot is not a connection. This, asserts the Ran, is not the case. Tekifah means sticking something together in any fashion, and not necessarily tying them into a knot. Therefore, putting the strings through the hole in the garment is one Tekifah, and making them into a knot is considered two Tekifos. (See, however, the CHIDUSHEI HA'RASHBA to the Gemara here who seems to agree with Rabeinu David regarding the definition of Tekifah.) (Y. MONTROSE)
39b----------------------------------------39b
2) HALACHAH: DOES THE MITZVAH D'ORAISA OF TZITZIS APPLY ONLY TO A GARMENT OF WOOL OR ALSO TO A GARMENT OF LINEN?
OPINIONS: The Gemara records a dispute about the type of material that a garment must be made from in order for it to be required to have Tzitzis according to Torah law. Rachvah says in the name of Rav Yehudah that Tzitzis-strings made from wool or linen fulfill the Mitzvah of Tzitzis for clothing made from any material, even a cloak of silk. The Gemara says that Rav Nachman disagrees with this, as Rav Nachman says that a cloak of silk is exempt from Tzitzis. The Gemara questions Rav Nachman's ruling from a Beraisa which explicitly states that a cloak of silk is required to have Tzitzis. The Gemara answers that the Beraisa is referring only to an obligation d'Rabanan, and not to a Torah obligation.
What is the Halachah? Does one fulfill the Torah obligation of Tzitzis with other materials, such as the commonly used cotton garment, or does one fulfill only a Chiyuv d'Rabanan with a cotton garment?
(a) The RIF, RAMBAM (Hilchos Tzitzis 3:2), and SHULCHAN ARUCH (OC 9:1) rule like Rav Nachman. They write that one fulfills only a Chiyuv d'Rabanan of Tzitzis with a garment made from cotton.
However, this ruling is difficult to understand. The Rambam himself (3:5) records the opinion of Rava, who says that strings of wool or strings of linen may be used for a garment made from any material, while strings of other types of material may be used only for a garment of that same material. Rava derives this from various verses, clearly showing that he maintains that this is a Torah law. Why, then, do the Rambam and the Shulchan Aruch (see OC 9:3) quote Rava's ruling when they rule in accordance with the view of Rav Nachman?
The BEIS YOSEF explains that the Rambam is not quoting Rava's ruling in the same context as Rava himself expressed it. Rava maintains that strings of wool or linen on a garment of any type of material is a fulfillment of the Torah obligation of Tzitzis. In contrast, the Rambam -- who rules like Rav Nachman -- maintains that for garments made of other materials (other than wool), Rava's ruling applies as a Halachah d'Rabanan. The Gemara alludes to this when it asks (while interpreting a Beraisa that makes a similar statement) that this Halachah would be logical if it is only d'Rabanan, since only Tzitzis of the same material (other than wool or linen) as the garment should suffice for a garment of that material. This is also apparent from the words of the Rambam, since he does not quote the verses from which Rava derives his ruling.
(b) TOSFOS (DH v'Rav Nachman) quotes RASHI and RABEINU TAM who rule in accordance with Rachvah in the name of Rav Yehudah, because Rava -- who is a later Amora -- rules this way. This is also the opinion of the MORDECHAI (#941), the SEMAG (Mitzvas Aseh 26), the ROSH (#18) and the TUR (OC 9). The REMA rules in accordance with this view as well. The Rosh has great difficulty with the view of the Rif, who rules like Rav Nachman. Since Rav Yehudah, Rachvah, and Rava all argue with Rav Nachman, why should the Halachah follow the view of one Amora against three?
HALACHAH: The HAGAHOS MAIMONIYOS (Hilchos Tzitzis 3:1) writes that a G-d-fearing person will use a garment of wool in order to remove himself from any doubt. This approach is also advanced by the AGUR (#8) in the name of the MAHARI MOLIN. Even though the Rema in DARCHEI MOSHE (OC 9) writes that he saw no one who was careful about this, the MISHNAH BERURAH (OC 9:5) writes that a G-d-fearing person will be stringent upon himself to make his garment out of wool in order to ensure that he fulfills the Torah obligation of Tzitzis according to all opinions. (See also ARUCH HA'SHULCHAN OC 9:25). The Mishnah Berurah adds that it is correct for a person to do this with both his Talis Katan and his Talis Gadol.
The IGROS MOSHE (OC 3:1) writes that even during the summertime one should wear a Talis Katan made from wool (which presumably is the view of the aforementioned Mishnah Berurah and the others, who write that one should be stringent and who do not differentiate between the seasons). He adds that this was his own practice. He explains that since the Gemara (41a) says that the Mal'ach told Rav Katina that a person who does not fulfill the Mitzvah of Tzitzis will be punished during a time of Divine wrath, one should ensure that he fulfills the Torah obligation of Tzitzis whenever possible.
However, the author of ZICHRON YAKOV (quoted in the KOL HA'TORAH journal, vol. 54, p. 237) writes that he heard that the CHAZON ISH did not wear woolen Tzitzis in the summertime. He suggests several possible reasons for the Chazon Ish's practice. It is possible that the Chazon Ish simply maintained that the opinion of the Rema was correct and he deemed it unnecessary to wear wool in the summer. Alternatively, unlike the Igros Moshe quoted above, the Chazon Ish maintained that since listening to the Chachamim is also a fulfillment of the Torah, fulfilling the Mitzvah of Tzitzis in a manner which is mid'Rabanan also serves to protect a person during a time of Divine wrath. (Y. MONTROSE)