27 Dec Best Time For Shema At Night
The first mishna in Berachos
The Rashba disagrees with the above Rabbeinu Yona and says that lekatchila, shema may be said from tzais hakochavim until a later zman. According to the Chachamim, one may read shema lekatchila until midnight. According to Rabban Gamliel, one may say shema lekatchila until alos hashachar, sunrise. The Rashba explains the gemara mentioned above as a restriction only for eating or drinking once the zman of shema arrives at tzeis hakochavim. Other activities may be permissible and one is not required to daven immediately at tzeis hakochavim. The Rashba says that his opinion is different from the Rif and other gedolim who hold that once it is tzeis hakochavim, one may not delay and he should recite shema and daven
The Tur in siman resh lamed heh paskens that mitzad the ikkar din one may wait lekatchila to say shema until the morning, but one should not eat or drink beforehand. The Bais Yosef explains that this is based on the Rashba, the Rosh and Tosfos. The Bais Yosef continues and says that according to the Rambam in Perek Alef Hilchos Krias Shema, halacha tes, the zman of shema is from tzeis hakochavim; however, if he was oveir and did not read it at tzeis, he may say shema until alos hashachar.
In the Shulchan Aruch, siman resh lamed heh, seif gimmel, the Mechaber writes that lekatchila one should say shema at tzeis hakochavim like the Rambam’s ruling. The Magen Avraham in seif koton tes says that it is forbidden to do any melacha from the time of tzeis hakochavim onward until one recites shema. Siman resh lamed bais lists things one is forbidden to do at mincha time in order to make sure one davens mincha on time. Included in these prohibitions would be eating a big meal. The Pri Megadim asks the following question. According to Rabbeinu Yona it should be forbidden to even sit and do nothing because one should immediately read shema at tzeis. Why is it only forbidden to eat or drink? The Magen Avraham holds that one may grab a quick nosh or a quick drink before reciting shema. He says it is not similar to kiddush and havdala where one is not allowed to even taste something, because kiddush and havdala
The Eishel Avraham differentiates that shema was not established right away. The Chachamim were concerned that one might forget to read shema so they said one should do so at tzeis hakochavim. This is why krias shema would have the same halachos as zman Mincha.
The Levush in siman resh lamed heh, seif gimmel says a different reason why one must read shema at tzeis; it is because of zrizin makdimin lemitzvos. If we hold like the Levush we see that mitzad dinei krias Shema it is not a din that it needs to be at tzeis, it is just for zrizim. This therefore would explain the difference between kiddush and shema. Thi