In the summer months it is customary for many to bring in Shabbos early. There are several issues that may arise in these situations. In specific, during the days when we count sefiras ha’omer the following issue often arises: When one accepts Shabbos early he may daven maariv although it is not yet night, however according to most opinions, krias shema must be repeated after nightfall. Additionally, one may not count sefira before night fall as well, and it too must be counted after dark.
One is prohibited to engage in certain activities, such as eating, up to a half hour prior to the time that one is obligated to recite Shema. If one started an activity after that time, he must stop and recite Shema at nightfall. If one started the activity prior to a half hour before the time to recite Shema, he does not have to stop the activity to recite Shema – provided that there is ample time to recite it thereafter.
When one accepts Shabbos early, he does not have to stop eating to say Shema, provided that he started eating at a time when he was permitted. However, if one made early Shabbos and postponed beginning the meal until after nightfall, he would be obligated to recite Shema prior to eating.
There is a question that often arises when one makes early Shabbos. It is generally already night at the conclusion of the Friday night seudah; thus, one is obligated to recite Shema. There are now two mitzvos that one is obligated in – Birchas Hamazon and reciting Krias Shema. So, which one should he perform first?
The Shagas Aryeh, in siman 21, discusses this question at length. He explains that the approach to answering this question begins with understanding the rule of tadir veshe’aino tadir, tadir kodem (the more frequent precedes the less frequent). We need to clarify which is the more frequent one. On the one hand the mitzvah of Birchas Hamazon can be performed many times a day, in fact as often as one wishes to eat bread; whereas the mitzvah of Krias Shema only applies twice a day.
The Shagas Aryeh proves from a Gemara (Zevachim 90b) that the frequency of a mitzvah is not determined by how often one can perform it, but rather by how often one is obligated to perform it. Although there are times when one is obligated to eat bread and bentch (recite Birchas Hamazon), such as three times on Shabbos and twice on Yom Tov, the obligation to recite Shema is far more frequent. Even though once one eats bread, he is thereby obligated to bentch, it is not considered an obligation (as it partains to this discussion), since he was not obligated to enter into that predicament.
The Shagas Aryeh concludes that one should first recite Krias Shema and then bentch, since the obligation to recite Krias Shema is more frequent.
I had thought to say that perhaps there is another component which needs to be addressed. Tosafos in Chullin 87a and the Rosh in Chullin (7:6) say that birchas hamazon is the completion of a meal. Perhaps there is room to say that since one was allowed to complete his meal (as he started prior to the time to say shimah) he should be allowed to recite birchas hamazon which is the completion of his meal.
Another common scenario occurs during the period of Sefiras Ha’Omer. If one was eating bread at night and had not yet counted Sefiras Ha’Omer, he will have two mitzvos that he will be obligated in – bentching and counting Sefirah. Once again, the dilemma arises: which mitzvah should precede the other? The Shagas Aryeh, in siman 22, says that the correct order differs if it is Shabbos or Yom Tov, or if it is a weekday. On Shabbos and Yom Tov when there is an obligation to eat bread and bentch, the mitzvah of bentching should come first since the obligation to bentch is more frequent than the obligation to count Sefirah. But on a weekday when there is no obligation to eat bread, the obligation to count Sefirah is more frequent. Thus, one should count Sefirah first, and then bentch. Additionally, in this scenario, if one had not yet recited Krias Shema its recitation would precede both Sefirah and bentching, since the obligation to recite Krias Shema is more frequent than both of those mitzvos.