Rabbanim,
I had intended to mail these questions about a week ago, but I don't see a copy of them in my outgoing mailbox, so perhaps my Internet provider failed me. Please forgive me if this letter is a duplication -- and if not, please forgive the large number of questions.
Berachos 31b-
Apparently, if someone fasts following a bad dream, he cancels the evil decree of that dream. If he fasts for this reason on Shabbos, he eliminates all the earlier evil decrees of his lifetime, but he then needs to also fast on Sunday to make up for failing to honor Shabbos properly.
a) Is this discussing a day fast, or a 24-hour fast? (I would presume a day
fast, as the person would have eaten an evening meal before falling asleep
and having the dream.) If it is a day fast, could a person fulfilling a
Saturday/Sunday fast then eat between havdala and shachar on Sunday?
b) May a fast because of a weekday dream be postponed, for example may the
evil decree of a Tuesday night dream be overturned by a Thursday fast, or
would the opportunity be lost?
c) Are there people today who undertake a Shabbos/Sunday fast? If so, could
a person voluntarily undertake a Shabbos/Sunday fast if he feels that he has
evil decrees hanging over him, or must he wait until a time that he has a bad
dream on a Friday night?
d) If a person has a bad dream before a holiday, is he likewise allowed to
fast, and then fast again the following day? Would such a fast also
cancel-out a lifetime's worth of evil decrees?
e) What would a person do if he had a bad dream before two or three days of
holidays and/or a holiday/Shabbat combination (as for health reasons there
would seem to be a limitation as to the number of days a person could fast)?
Berachos 35b quotes Erubin 26b that one who takes a vow to abstain from eating is allowed to use water and salt.
f) Does a fast to overturn a bad dream fall into this category (that one may
drink water)?
g) If water (and salt) aren't considered sustaining food, then why isn't
water allowed on all fast days?
Again, I apologize for the large number of questions.
Bechavod rav,
Charles Stein
a) Private, individual fasts are generally day-fasts (from dawn to nightfall). Consequently, one could eat after Havdalah, before dawn on Sunday. (See the laws of private fasts in Shulchan Aruch OC 562-568.)
b) A fast for a bad dream may not be postponed (Shabbos 11a; Shulchan Aruch OC 568:2).
c) See Shulchan Aruch OC 288:3, 5, and 8 concerning fasting on Shabbos for the sake of repentance, and whether the practice to fast on Shabbos for a bad dream applies in our days. The Mishnah Berurah (288:5) writes that one may not fast on Shabbos for his sins or for the sake of repentance, with the exception of a person who also experiences physical distress when eating.
d) Yes, Yom Tov is the same as Shabbos with regard to fasting for a bad dream (but see Shulchan Aruch 288:5). Such a fast would also cancel out evil decrees, because one sees everyone experiencing Simchah and is distressed.
e) One would fast one day, and make up the second fast after Yom Tov (Shulchan Aruch 288:4).
f) No.
g) Because one gets pleasure from it as a thirst-quenching drink, even though has no nourishing properties like food.
All the best,
Yisroel Shaw