Question: If a person wore his talis katan the entire night long (sleeping or awake), should he make another bracha in the morning?
Answer: That is the famous Shavuos question! After learning the entire night, everyone wonders whether or not he should make the bracha on his tzitzis in the morning. For those who don a talis gadol, there is an easy way to get out of the question: just make the bracha on the talis gadol and have in mind to include the talis katan, as we have learned. The question would be for unmarried boys and men who are not wearing a talis gadol.
The answer to the question revolves around another fundamental question: Is there a mitzvah to wear tzitzis on a four-cornered garment at night. If during the night, there is a cessation of the mitzvah, then a new bracha would be required in the morning, even though one did not physically remove the garment. If the mitzvah continued uninterrupted, then without the physical removal of the garment, there would be no basis to make a new bracha. At first glance, it would seem that there is no mitzvah at night, because the Torah stipulated that we should SEE our tzitzis and remember the mitzvos. From this the rabbis derive that nighttime, which is not a time for seeing, is not a time for the mitzvah. However, upon further investigation, one discovers that it is not so clear what exactly is excluded: Is one exempt from the mitzvah at night, even if he wears the same garments that he wears during the day; OR is one exempt simply from putting tzitzis on those garments that one typically wears at night? According to the second interpretation, if the person was wearing his daytime clothing throughout the night, there would have been no cessation of the mitzvah at all.
The halacha does not resolve which interpretation of the nighttime exemption we should follow. In practice, therefore, we follow the golden-rule of brachos: “When in doubt, leave it out!” More preferred, however, is to have the talis katan in mind when making the bracha on the talis gadol, as we have said. If one does not wear a talis gadol, then he should listen to the bracha from one who does. That is the solution to the famous Shavuos question!
We have already learned that if a person must don his talis katan before it is light enough (i.e. ‘mi-she-yakir’), he should not make the bracha at that time. Rather, he should wait until the time comes, then make the bracha and rub his hands along the tzitzis, which represents his renewal of the mitzvah performance.
Question: Strictly speaking, what exactly is the mitzvah of tzitzis?
Answer: If a person is wearing a garment with four corners (and other specifications), he must attach tzitzis to that garment. One does not transgress this mitzvah unless he is wearing that kind of garment without the tzitzis. Nevertheless, we will learn that it is of great importance to obtain a four-cornered garment, in order to fulfill the mitzvah.