http://www.chabad.org/library/article_cdo/aid/927994/jewish/Laws-of-Tzitzit.htmSpeak to the children of Israel, and say to them that they shall make for themselves fringes on the corners of their garments, throughout their generations, and that they shall affix a thread of sky-blue [wool] on the fringe of each corner.
This shall be tzitzit [fringes] for you, and when you see it, you will remember all the commandments of G‑d to perform them, and you shall not wander after your hearts and after your eyes after which you are going astray.
So that you shall remember and perform all My commandments, and you shall be holy to your L‑rd.Numbers 15:38–40
We are told that the mitzvah of tzitzit is equivalent to all the mitzvot, because it reminds us of all of them.1 As Rashi explains,2 the gematria (numerical value) of the word tzitzit (ציצית) is 600. Six hundred, plus the five knots and the eight strands, equals 613, which is the number of the mitzvot.
Our sages say that one who fulfills this mitzvah properly merits to have a wife and children.3 He is also protected from sin,4 and in that merit he is assured that he will see the face of the Shechinah (Divine Presence).5
This mitzvah is not an obligatory one. Only when one is wearing a garment of four (or more) corners is he is required to affix tzitzit to the corners. If he is not wearing such a garment, he does not transgress by not wearing tzitzit.
Despite this, an angel taught Rabbi Ketina6 that at times of divine wrath, G‑d punishes people for not assiduously pursuing mitzvot, even those who choose not to wear a four-cornered garment in order to exempt themselves of this special mitzvah. For this reason, it is proper that men and boys wear a four-cornered garment, with tzitzit affixed to it, every day. This garment is called a tallit katan (“small shawl”), or simply tzitzit.
In fact, according to the master Kabbalist the Arizal, it is proper to wear the tallit katan at all times, even at night7—although halachically a “night garment” is exempt from tzitzit.8
As the laws of tzitzit are quite extensive, this article will focus on some of the more common issues. In addition, we will address the laws of the tallit katan rather than the laws of the tallit gadol (the larger tallit worn only for prayers).9
The GarmentIn order for a garment to require tzitzit, it must have four corners. It must be a garment for the body and not just the head (such as a shawl).10 But, unlike an ordinary shirt, the four corners must include two in the front and two in the back.11
If the front and the back of the garment are connected at the sides, a clear majority must still be disconnected.12 According to R. Schneur Zalman of Liadi,13 the tallit katan should be completely open on both sides, and not be attached with any stitches or clasps. Certainly, the garment should not have sleeves. The garment must be of a woven material,14 and preferably, it should be made of wool and be white.15
The TzitzitThe strings of the tzitzit need to be spun specifically for the sake of the mitzvah of tzitzit. For this reason, the spinning has to be done (or at least overseen) by a Jew over the age of bar mitzvah.16 It is therefore very important to buy tzitzit that are certified by a reliable supervising agency. Otherwise, one may mistakenly wear a pair of tzitzit that is not halachically acceptable.
If the strings tear, the laws are as follows:
If one of the eight strings is ripped off entirely, the tzitzit are still kosher.
If a second one is ripped completely off, the tzitzit may or may not be kosher, depending on various factors.
If three strands rip, it may not be kosher even if they do are not ripped off completely.17
Techelet
In recent years there have been several attempts to revive the mitzvah of dyeing one strand of the tzitzit with techeilet.
True techeilet is a special blue dye made from the blood of a fish (or sea creature) called the chilazon. In ancient times, one of the strings of the tzitzit was dyed with this dye. The color was to remind us of the heavens, and thus of the throne of divine glory. We have lost the tradition as to the identity of this creature. Nevertheless, based on various sources and discoveries, there are many people who use the blood of a sea snail called murex trunculus.
However, R. Shalom DovBer Schneersohn, the fifth Chabad-Lubavitch rebbe, and many other Torah giants do not agree that this is the true chilazon mentioned in the Torah. They believe that the chilazon will re-emerge only with the coming of Moshiach.18
Putting on the Tallit
Before donning the tallit katan or tallit gadol, one should separate the strands of the tzitzit and ensure that all of the strands are in order.19 (But if doing so will cause him to miss the minyan, he may don the tallit without doing this.20)
If one slept in his tallit katan, he may not recite a blessing on it in the morning. Rather, he should keep the tallit katan in mind when he recites the blessing on the tallit gadol.21
When putting on the tallit katan or tallit gadol, one should keep in mind that he is wrapping himself in tzitzit in order to remember and fulfill all the commandments, as the verse says: “You will see them, and remember all the commandments of G‑d.”22
It is proper to wear the tzitzit strands in a visible way, so that they remind one of the mitzvotThe blessing on the tzitzit must be said while standing.23 If one is sick or weak, he may make the blessing while sitting.24
Wearing the Tallit Katan
It is proper to wear the tzitzit strands in a visible way, so that they remind one of the mitzvot, as the verse says: “You will see them and remember all the mitzvot of G‑d.” If one is afraid of being mocked in public, he may tuck them into his clothes.25 The custom of the Arizal was to keep the tallit katan completely covered,26 but this is not proper for the average person, who should rather keep the actual tzitzit uncovered.27