“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 simply exempt from putting tzitzis on those garments that one typically wears at night?” (Ed: Do you see the difference between the two interpretation?)
2) Rosh interprets: the exemption of night is garment-related – i.e. a daytime garment is alwaus obligated, even when one wears it at night; a nighttime garment (i.e. a four-cornered night-shirt) is exempt, even if he wears it during the day.
Which opinion does the halacha favor? It doesn’t - it bids us to be stringent on both counts: don’t wear a four-cornered garment without tzitzis unless it is both a nighttime garment and it is night. However, don’t make a bracha over tzitzis unless it is both a daytime garment and it is day!
Did you know… why some shuls have a custom for the chazzan not to wear a talis for maariv? The reason for the this custom is so as not to give the impression that we completely adopt the opinion of the Rosh. This is only a custom; it is halachically acceptable for the chazzan to wear the talis, particularly if he is not wearing a formal over-garment, such as a jacket.
Question: Why do men don taleisim on the eve of Yom Kippur?
Answer: On Yom Kippur we are like like ‘malachim’ (angels)! In fact, for this reason it is proper to keep it on through maariv after Yom Kippur as well.) Now, based upon what we have learned today, one must make the bracha before it gets dark (i.e. ‘shkia’ – sunset) before Yom Kippur! (Perhaps even a few minutes after shkia…)
Question: According to the Rambam, if I sleep in bed during the day, how can I cover myself with a sheet – isn’t that a four-cornered garment being worn during the day?!
Some authorities answer: That’s not called wearing; it’s called covering, and so it does not require tzitzis! Some authorities disagree with that explanation. They maintain that indeed, one would be required to round off one of the corners of the sheet! (Note: Mishnah Berura writes that one who wishes to be strict need do so only if the sheet is made out of wool!)