Eating Before Friday Night Kiddush
In keeping with the rabbinic prohibition against eating before one is about to fulfill a mitzvah, it is prohibited to eat before reciting kiddush on Friday night. Generally, eating prior to fulfilling a mitzvah is forbidden due to concern that one will become engrossed in the meal and forget to perform the mitzvah. But unlike other mitzvos, where it is forbidden to have a meal before performing them, it is prohibited to have even a morsel of food or a drink of water before reciting kiddush. This special stringency was established, in part, because the Sages instituted that kiddush be recited immediately when Shabbos begins,[i] before partaking of any other food or drink, including even a small amount of water.[ii] Rinsing out the mouth,[iii] or taking medication with or without water, is permitted.[iv]
Since women, too, are obligated to recite or hear kiddush, they, too, may not eat or drink before kiddush. But children under the age of bar or bas mitzvah are permitted, when necessary, to eat before kiddush.[v]
The prohibition against eating and drinking on Friday night begins as soon as one accepts Shabbos, or inevitably at sunset. Women generally accept Shabbos when they light candles, and they should not eat or drink after that. However, if a woman is extremely thirsty after lighting candles, she may take a drink until she verbally accepts Shabbos.[vi]
A person who is certain that he will not have wine [or any other beverage] or challah over which to make kiddush may eat without reciting kiddush.[vii]
[i] Mishnah Berurah 271, note 11 based on Shulchan Aruch Harav 271:9. See also R’ Akiva Eiger to Magen Avraham 271:6.
[ii] See Mekor Chayim, Orach Chaim 431:2 (Beiurim) and Beiur HaGra 271:4. On Shabbos morning, too, it is forbidden to partake of any food or drink, including water, before kiddush; see explanation in Maggid Mishneh, Shabbos 29:10.
[iii] Mishnah Berurah 271, note 13.
[iv] Minchas Yitzchak VIII, 18.
[v] Chayei Adam 66:10; Mishnah Berurah 269, note 1
[vi] See Da’as Torah 271:4. A nursing mother who knows that she will need to drink after lighting candles should stipulate that she is not accepting Shabbos until she is finished drinking (Ketzos Hashulchan 74:17; 79:3).
[vii] Mishnah Berurah 289, note 10. If he expects that he will have wine or challah before midnight, he should wait until then to make kiddush. If he expects them later than midnight, he is not obligated to wait and he can eat before making kiddush (ibid.).