"Speak to the children of Israel and you shall tell them to make for themselves fringes on the corners of their garments, throughout their generations, and they shall make a thread of sky blue on the fringe of each corner. These shall be fringes for you, and when you look at them, you will remember all of G-d's commands to perform them. And you shall not wander after your hearts and after your eyes which you are going astray. You shall remember all my commandments and be holy to your G-d. I am the L-rd your G-d who took you out of the land of Egypt to be your G-d. I am the L-rd, your G-d." -Numbers 15:38-41
This lengthy passage, which also happens to be the third paragraph of the Shema, describes the mitzvah of wearing fringes, or tzitzit (ציצית), on one's garment. If clothes mean nothing until someone lives in them, then what does wearing tzitzit mean when a Jew wears them?
The biblical verse itself already gives an answer: to remember the commandments. I'm not here to diminish that response because a) it is straight from the Torah, and b) it is correct. However, rabbinic commentary provides further insight. Menachot 43b went as far as saying that performing the mitzvah of tzitzit is as if one performed all the mitzvahs. Why? Because seeing leads to remembering, and remembering is supposed to ultimately lead to doing.
This leads into the Talmudic passage in the next folio in Menachot 44a. A Jewish man was going to consort with a well-known, non-Jewish harlot for a hefty price. Before they engaged in sexual congress, the tzitzit slapped him in the face. The tzitzit were such a strong reminder that the man did not go through with it. More to the point, the harlot was so impressed that she herself ended up converting to Judaism. Even if the slap in the face was a metaphorical one, it still illustrates the power of how seeing invokes memory and subsequent action. The idea of memory would also explain why this passage is in the Shema and why the passage has a reminder to remember the Exodus at the end. As R. Baruch Epstein points out, it is not enough to remember: we also have to act. If the tzitzit do not prompt us to act, then they have not had the full effect.
The saying goes that the devil is in the details. Personally, I prefer to say that G-d is in the details, but it's the same general idea: details provide deeper insight. The particulars of the mitzvah of tzitzit also bring up a few follow-up questions that lead to that deeper insight:
- Why are there 39 windings? To make the tzitzit, you have to wind the thread in order to create the tzitzit. In Ashkenazic tradition, the number of windings is 39 (see below). Why the breakdown of 7-8-11-13? Seven stands for the seven days of Creation. Eight stands for the number of transcendence that goes beyond nature. Eleven is for the Hebrew letters ו-ה under Jewish numerology (gematria), which also are the last two letters of G-d's name in the Tetragrammaton. Thirteen represents for the gematria of אחד, or the Hebrew word for "one," which represents G-d's Oneness (R. Aryeh Kaplan).
- Why are the threads loose? The loose threads are like the unwoven portion of the tallit (prayer shawl). They represent the incompleteness in G-d's metaphorical garment, an incompleteness that unwoven part that man is supposed to complete (R. Meir Simcha of Dvinsk). I actually have an alternative response. When looking at an individual mitzvah (which is represented by a loose tzitzit thread), it seems isolated or inexplicable. In reality, the mitzvot are tied together to the greater purpose of serving G-d, much like the loose threads are tied together as one entity.
- Why are there 8 threads? During Passover, we sing a song called "Who Knows One?" (Echad Mi Yodea). When we sing the song and reach the part of "Who knows eight", what is the response? "Eight days for circumcision." Circumcision represents the covenant between the Jewish people and G-d. Much like circumcision is supposed to be a link with the Transcendental, so are the tzitzit (Maharal).
- Why are the threads placed at the edge of the garment? As R. Dr. Asher Meir puts it, the outward-flowing fringes represents the openness we should have to the world, and how we should reach out to it. The tzitzit thusly represent how we are the interact with the world: openly, instead of closed off from it. Much like the tzitzit can only extend so far, the mitzvahs also put limitations on what Jews can do. This represents the paradox between being free and feeling a sense of obligation towards G-d and Judaism: we are to maximize our experiences while adhering to the mitzvahs.
- Why is the garment with the tzitzit a square? The Sages taught that a four-sided figure is an archetype of something manmade. The square reminds us of our responsibility in the world (Jerusalem Talmud, Nedarim 3:2).
- Why is supposed to be worn during the day only? The nighttime is supposed to be a time of inactivity and turning more inwards, which is why it is commanded during the daytime only (Shulchan Aruch, O.C. 18). I would surmise that it is during the daytime only because for the mitzvah of tzitzit to work, you have to see them, much like the biblical verse states. In premodern times, one could not see much at night, which included being unable to see tzitzit. In modern times, we can see them, which under that argument, would extend the mitzvah to the evening.
- Why is there a blue thread? The Torah says that one of the threads has to be sea blue. The Talmud (Chullin 89a) provides an explanation. The blue thread is blue like the sea, which is similar to the blue of the sky, which is similar to the color of the Throne of Glory. There is further symbolism here. The sea represents immersing oneself in Torah. The sky represents doing mitzvot for the sake of Heaven. From there, one can reach the Throne of Glory, which represents the high end of our potential.
- Why is the mitzvah not obligatory? If the purpose is to remind us of all the mitzvot, surely it should be obligatory. Yet under Jewish law, it is not. Why? Because the mitzvot form the life of a Jew. They are all-encompassing. Since it can be quite the undertaking, it is only when Jews obligate themselves to take on the mitzvah of wearing tzitzit that Jews truly express a love for G-d.