Shulchan Aruch, Orach Chayim 24 — שולחן ערוך, אורח חיים כד

Wearing a tallit katan all day, holding and looking at the tzitzit during Kriyat Shema, and the reward and punishment of this mitzvah.

seif 1 The Mechaber writes that a person whose clothing has no four corners is not obligated in tzitzit. Even so, it is good and proper for every person to wear a tallit katan (a small four-cornered garment with tzitzit) all day, so that he remembers the mitzvot at every moment. The Gra traces this reason to the Gemara in Menachot: seeing leads to remembering. The Mishnah Berurah, citing the Tur, compares it to tying a knot in a belt as a reminder of something one was warned about. The Mechaber continues that this is why the tzitzit have five knots, one for each of the five Chumashim. They hang from four corners, so that whichever way a person turns, he remembers. He adds that it is proper to wear it over the clothing. The Aruch HaShulchan applies this to the tallit gadol (the large tallit) worn at Tefillah. It goes over all the clothes so that a person sees the tzitzit.

The Mechaber writes that, at the least, one should take care to wear tzitzit during Tefillah. The Gra notes that he follows the Rambam and the Tur here, even though strict law does not require it. The Mishnah Berurah adds Kriyat Shema. He cites the Zohar, as the Magen Avraham does: one who says Kriyat Shema without tzitzit gives false testimony about himself. He reads the passage of tzitzit and does not fulfill it. The Mishnah Berurah also cites the Chayei Adam, who faults the common practice of praying on the road without a tallit gadol. The tallit katan is usually not made correctly in every detail, so it is not fit for a bracha. People also sleep in it at night. The Aruch HaShulchan cites the Gemara in Menachot that one with no tzitzit on his garment transgresses five positive mitzvot. He explains that this applies when one wears, without tzitzit, a garment that requires them.

seif 2 The Mechaber writes that it is a mitzvah to hold the tzitzit in the left hand, against the heart, during Kriyat Shema. The hint for this is the pasuk "vehayu hadevarim ha'eleh … al levavecha," which places these words upon the heart. The Gra and the Aruch HaShulchan find the source in the Midrash Shocher Tov. There David says he holds the tzitzit against his heart while reading Kriyat Shema. The Mishnah Berurah explains that the heart sits toward a person's left. He adds that tzitzit have a special strength to rescue someone from the yetzer hara (the inclination to sin), which other mitzvot lack, as the story in the Gemara in Menachot shows. The Magen Avraham and the Mishnah Berurah cite the writings of the Arizal on how this is done. One holds the tzitzit between the ring finger and the little finger. On reaching the passage of tzitzit, one takes them in the right hand as well and looks at them. One keeps holding them until the words "ne'emanim venechemadim la'ad" (faithful and desirable forever), then kisses them and lets them go. The Aruch HaShulchan writes the same.

seifim 3–4 The Mechaber writes that looking at the tzitzit while wrapping oneself in the tallit, as one says the bracha, is a good practice. The Mishnah Berurah gives the reason from the pasuk "ure'item oto uzechartem" (you will see it and recall). Sight brings a person to remember, and memory brings him to act. The Mechaber records a custom of looking at the tzitzit on reaching "ure'item oto" (you will see it) and placing them on the eyes. He calls it a beautiful custom and chibuv mitzvah (an expression of love for the mitzvah). The Rema adds that some also kiss the tzitzit when they look at them. The Mishnah Berurah reports, in the name of early authorities, a promise for one who passes the tzitzit over his eyes during the passage of tzitzit. He will not come to blindness. He rules that a blind person still holds the tzitzit during Kriyat Shema, since other people can see them. But he does not pass them over his eyes, because that would look like mockery.

seif 5 The Mechaber writes that one looks at the two tzitzit in front of him. Together they have ten knots, a hint to the sefirot. The Magen Avraham (citing the Recanati) and the Mishnah Berurah explain the term this way. The Mishnah Berurah adds that the sefirot are bound and united with one another. The two tzitzit also have sixteen threads. With the ten knots, that makes twenty-six, the numerical value of Hashem's four-letter Name. The Aruch HaShulchan describes this as a practice of holding the two front tzitzit during Kriyat Shema.

seif 6 The Mechaber writes that the punishment for neglecting tzitzit is great. He applies to such a person the verse about grasping the corners (kanfot) of the earth. The Aruch HaShulchan gives its continuation (Iyov 38:13), which speaks of the wicked being shaken out of it. The Mechaber adds that one who is careful with tzitzit merits to see the face of the Shechinah (the Divine Presence), following the Gemara in Menachot, as the Gra notes. The Magen Avraham writes that one should make a beautiful tallit, because of the verse "zeh Keli ve'anvehu" (I will beautify Him). The Mishnah Berurah extends this to making beautiful tzitzit, and to doing every mitzvah as beautifully as possible. He rules that verses of the Torah may not be embroidered on a tallit. If they were already embroidered, one may still say the bracha on it. The Aruch HaShulchan also forbids embroidering verses on a tallit.