The Torah in Parashat Shelah (Bamidbar 15:38) introduces the command of Sisit, requiring that special strings be affixed to one’s four-cornered garment.
The Sefer Ha’hinuch explains that the Torah requires affixing Sisit to one’s garment in order for us to remember our obligations to G-d, that we are duty-bound to observe His commands. When a servant wears his master’s seal on his garment, the Sefer Ha’hinuch writes, this is the most effective way of always remembering his obligations to his master. And so we, too, wear Sisit, the “seal” of our Master, reminding us that we must always be subservient to His will.
Moreover, the Sefer Ha’hinuch writes, the Sisit alludes to our obligation to fulfill the Misvot. The word “Sisit” in Gematria equals 600, and when we add the eight strings and five knots, we arrive at 613, the number of Misvot in the Torah.
The Sefer Ha’himuch also adds a deeper insight into the symbolism of the Sisit, explaining that it represents the subservience of both the body and the soul to the Almighty. The Gemara in Masechet Nidda (25) teaches that when an infant is formed, the arms and legs resemble strings, and thus strings serve as a symbol of the human being. The Sisit strings include both white strings and strings colored blue with the Techelet dye, and the Sefer Ha’hinuch posits that these two kinds of strings symbolize the body and the soul. The human body was created from the ground, and according to tradition, the ground came into existence through a white substance resembling snow. Thus, the white Sisit strings represent the body, whereas the blue strings, which resemble the heavens, represent the soul, which originates from the heavens. The Techelet string is wrapped over the white string, to symbolize the superiority of the soul over the body. We wear both to demonstrate that both our body and our soul must be subservient to the Almighty.
Different views exist as to how many wrappings are made with the Sisit – either seven or thirteen. The seven wrappings represent the seven layers of the heaven, and the Gemara in Masechet Hagiga teaches that there are spaces in between the seven heavens, such that there are in total thirteen layers. According to both views, then, the Sisit strings bring to mind the heavens, thus reminding us of our obligations to G-d.
The Misva of Sisit requires affixing strings to each corner of a four-cornered garment. If a garment has more than four corners, then Sisit are required on the four furthest corners.
If the Techelet dye is not available, the Misva of Sisit can nevertheless be fulfilled without it, with only white strings (and, conversely, if one only has Techelet strings, he can fulfill the Misva even without white strings). Indeed, as the Sefer Ha’hinuch writes, the Jewish Nation for centuries has not had access to the Techelet dye, and thus fulfilled the Misva of Sisit with only white strings. Nowadays, there are indications that the authentic Techelet dye might have been rediscovered, perhaps signaling that as we reach the time of the final redemption, we are moving closer toward the fulfillment of the Misva of Sisit in the ideal manner, with the Techelet dye.
The wool used for the Sisit strings must be spun “Li’shmah” – with the intention that the strings are being prepared for the sake of the Misva of Sisit. If the wool was spun by a gentile, the Misva of Sisit cannot be fulfilled with these strings.
The Misva of Sisit applies only to garments that are being worn. If one has a four-cornered garment in his closet which he does not wear, he is not required to affix Sisit to that garment. In Halachic jargon, Sisit is a “Hobat Gabra” – an obligation that rests upon the person, as opposed to a “Hobat Mana” – an obligation applicable to the garment. It is only when the garment is worn by a person that it requires Sisit strings.
The Torah obligation of Sisit applies only to garments made from wool or linen; garments made from other materials require Sisit Mi’de’rabbanan (by force of Rabbinic enactment).
Halacha follows the view of Bet Hillel, that the prohibition of Shaatnez (wearing a garment containing both wool and linen) does not apply to Sisit. The Torah in the Book of Debarim (22:11-12) juxtaposes the Shaatnez prohibition with the Misva of Sisit, indicating that the obligation of Sisit overrides the prohibition of Shaatnez. Therefore, according to Bet Hillel, a linen garment requires Sisit, even though the Techelet strings are always made from wool, as the color of the Techelet is properly absorbed only in wool. Since the prohibition of Shaatnez is not applicable to Sisit, the woolen Sisit strings must be affixed even to a linen garment. Nevertheless, Bet Hillel maintained, when one wears a linen garment, he may not affix woolen Techelet strings, as a safeguard enacted by the Sages. There was a relatively inexpensive dye called “Kala Ilan” that strongly resembled Techelet, and if somebody would dye his woolen Sisit with “Kala Ilan” instead of Techelet, and affix the strings to his linen garment, he would be in violation of the Shaatnez prohibition. Since these strings are not dyed with Techelet, they do not fulfill the Misva, and thus the prohibition of Shaatnez remains in force. To protect against this violation, it was enacted that when affixing Sisit to a linen garment, Techelet should not be worn.
Fundamentally, the Misva of Sisit requires only affixing Sisit strings to a four-cornered garment which one decides to wear. Strictly speaking, there is no obligation to specifically wear a four-cornered garment in order to fulfill the Misva of Sisit. However, the Sages instructed that it is proper to make a point of wearing a four-cornered garment so we can fulfill this precious Misvas. In fact, the Gemara teaches that one who ensures to fulfill this Misva will be rewarded in the next world with having many servants tending to him. Specifically, the Gemara teaches, each of the seventy nations will supply ten servants for each of the four corners – for a total of 2800 servants. Certainly, then, it is worthwhile to make a point of wearing a four-cornered garment in order to be able to fulfill this Misva and earn its rewards. Moreover, the Gemara teaches that while generally Hashem does not punish a person for neglecting to perform a Misvat Aseh (affirmative command), a person can be subject to punishment for this neglect during an “Idan Rit’ha” (“period of wrath”), when the divine attribute of justice is in force. As we never know when an “Idan Rit’ha” might befall the world, we are well-advised to pursue every Misva opportunity, including the relatively easy Misva of wearing Sisit.
Additionally, the Sages teach us that one who ensures to properly fulfill the Misvot of Tefillin, Sisit and Mezuza is guaranteed not to sin.
This Misva applies in all places and times, and only to males. However, this Misva does not apply at night, and thus it falls under the category of “Misvot Aseh She’ha’zman Gerama” (affirmative commands that are limited to specific times), from which women are exempt. Nevertheless, in principle, a woman who wishes to fulfill this Misva may do so. And, some authorities maintained that a woman who volunteers to perform a time-bound Misva from which she is exempt recites a Beracha when performing the Misva, and thus, according to this view, a woman who chooses to wear Sisit would recite a Beracha. Clearly, however, it is not customary for women to wear Sisit.
If one wears a four-cornered garment that is made from wool and linen, and which is the minimum size that requires Sisit, and he does not have Sisit on the garment, then he violates this affirmative command. If the garment is made from a different material, the individual has violated a Rabbinic enactment.
It should be noted that the obligation of “Hiddur Misva” requires using aesthetically pleasing articles for the performance of Misvot. Accordingly, one must ensure that his Sisit, and his Tallit, are clean and neat. Unfortunately, there are many people who wear the same Tallit for many years, during which it becomes dirty and worn, and thus looks unbecoming. Just as one purchases a new suit every so often, it is proper to purchase new Sisit and a new Tallit every so often to ensure that the garment is befitting the fulfillment of the Misva.