ציצית חובת גברא הוא אולא חובת מנא שכל זמן שאינו לובש הטלית בפטור מציצית ולפיכך אינו מברך געל עשיית הציצית שאין מצוה דאלא בלבישתו:
The mitzvah of tzitzis is an obligation upon the person (chovas gavra), and not an obligation upon the object (chovas mana) — that is, it is not the garment itself that must have tzitzis regardless of use. For as long as one is not wearing the garment, he is exempt from tzitzis; the duty is triggered by wearing, not by mere ownership of a four-cornered garment. Therefore one does not recite a blessing upon the making of the tzitzis (i.e., when attaching the strings to the garment). Since there is no mitzvah except in the wearing of it — so the blessing belongs to the act of donning, not to the act of manufacture.
ס״ק אולא חובת מנא
(א) ולא חובת מנא - עיין לעיל סימן י"ז סק"ה מש"ש:
On the phrase 'and not an obligation upon the object': See above in siman 17, se'if katan 5, and what is written there (מש"ש = מה שכתוב שם) — the discussion of this point is developed there.
ס״ק בפטור מציצית
(ב) פטור מציצית - אע"ג דכתיב ועשו להם ציצית על כנפי בגדיהם מ"מ מדכתיב קרא אחרינא גדילים תעשה לך על ארבע כנפות כסותך אשר תכסה בה משמע דוקא כשמתכסה בה:
On the phrase 'he is exempt from tzitzis': Although it is written, 'And they shall make for themselves tzitzis on the corners of their garments' — which might have implied that any garment with corners requires tzitzis. Nevertheless, since another verse states, 'You shall make for yourself twisted fringes on the four corners of your covering with which you cover yourself.' This implies that the obligation applies specifically when one actually covers himself with it — hence an unworn garment is exempt.
ס״ק געל עשיית הציצית
(ג) על עשיית הציצית - ר"ל בעת הטלתן בהבגד אלא אח"כ כשמתעטף בו מברך להתעטף. ואם נפסקו אחר שלובשו צריך לפשטו ולעשות בו ציצית ולברך כשחוזר ולובשו אף שלובשו תיכף:
On the phrase 'upon the making of the tzitzis': That is to say, one does not bless at the time of placing the strings onto the garment. Rather, afterward, when he wraps himself in it, he recites the blessing 'lehisatef ba-tzitzis.' And if the strings became severed (i.e., invalidated) after he had already put it on. He must remove the garment and make new tzitzis on it. And he recites the blessing anew when he puts it back on. Even if he dons it again immediately — the fresh act of wearing warrants a fresh blessing.
ס״ק דאלא בלבישתו
(ד) אלא בלבישתו - וה"ה במזוזה דקי"ל חובת הדר היא אין לברך על המזוזה רק כשהוא נכנס לדור בהבית תיכף ומיד דאז הוא ממש דומיא דעטיפה או כשכבר דר בה [ברכ"י וכן משמע מדברי המ"א להמעיין בו היטיב ועי"ש עוד במ"א ובברכ"י ובתשובת רע"א בסוף סימן ט']:
On the phrase 'except in the wearing of it': And the same applies to mezuzah, regarding which we have an established ruling (קי"ל = קיימא לן) that it is an obligation of the dweller (chovas ha-dar). One should not recite the blessing on the mezuzah except when he is entering to dwell in the house right then and there. For then it is truly analogous to the wrapping in a tallis — the blessing accompanies the onset of the obligating act. Or when he already dwells in it (and is affixing the mezuzah at that point). [Sources: Birkei Yosef (ברכ"י); and so it is implied from the words of the Magen Avraham (מ"א) to one who examines him well; and see further there in the Magen Avraham and in the Birkei Yosef, and in the responsa of Rabbi Akiva Eiger (רע"א) at the end of siman 9.]
עשה טלית לצורך תכריכין אף על פי שלובשו לפעמים בחייו הפטור:
If one made a garment for the purpose of burial shrouds (tachrichin). Even though he wears it on occasion during his lifetime. It is exempt from tzitzis, since it was designated for the dead, who are exempt from mitzvos.
ס״ק הפטור
(ה) פטור - האחרונים מסקי דדוקא לדעת הרא"ש דפטור לעיל בסימן י"ח כסות המיוחד ללילה אפילו ביום והא נמי לכסות לילה דמי שהרי מת פטור ממצות אבל לדעת הרמב"ם דמחייב כסות לילה ביום גם בזה חייב לפיכך לדידן יעשה בו ציצית ולא יברך. מוכרי הבגדים שלובשין ומכוונין להראות להקונים מדתן פטורין ואם לובש אותן להעביר בזה את המכס אפשר דחייב בציצית כמו גבי כלאים:
On the word 'exempt': The Acharonim conclude that this exemption holds specifically according to the view of the Rosh, who exempts (above in siman 18) a garment designated for night even when worn by day. And this case too is comparable to a night-garment, since a dead person is exempt from mitzvos — so a shroud is like a garment never subject to the daytime obligation. But according to the view of the Rambam, who obligates a night-garment when worn by day, in this case too it would be obligated in tzitzis. Therefore, for us — to satisfy both views — he should make tzitzis on it but not recite a blessing. Garment-sellers who wear the garments intending to show the buyers their size are exempt, since they are not wearing them for the sake of wearing. But if one wears them in order to evade the customs duty (i.e., to smuggle them through as if they were his personal clothing). It is possible that he is obligated in tzitzis, just as we find regarding the prohibition of kilayim in such a case.