Dear Rabbi
If someone takes there tzitzis at night and hasn’t yet kiryat shema (as they davened mariv before nacht), is there a requirement to put on them on again when saying shema?
Answer:
The Mishna Brura at the beginning of Siman 24 brings from the Zohar that one must were Tzitzis when he is reciting Shema. However this is only by day when one fulfills the mitzva of Tzitzis. At night the common custom is to wear the tallis katan until going to sleep, but there is no specific obligation to wear them for kriyas shema.
