I had a Lubavitcher classmate in high school who used to spill off from his cup whenever he would drink anything. He claimed it was a minhag.

What is the reason/source for this practice?

1 Answer 1


It's from the Gemara, Chullin 105b (bottom):

ואמר אביי: מריש הוה אמינא האי דשדי מיא מפומא דחצבא - משום ציבתא; אמר לי מר, משום דאיכא מים הרעים

"Abaye says: I used to think that the reason people pour out some water from the lip of a pitcher [before drinking from it] is because of floating bits [Rashi: twigs and straw that are floating on the water]; but my teacher [Rabbah] told me that it's because of 'evil waters' [Rashi: a shed (demon) may have drunk from it, and this corrects the problem]."

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    This doesn't follow for two reasons. First many meforshim(the Ben Ish Hai in Benayahu Ben Yehoida, as well as the Arizal in Maamre Hazal), state that this is only for drinks that have been left uncovered and unsupervised- from whence is derived a minhag to cover one's drinks. Second, as this is reportedly a Chassidic custom, and the Baal Shem Tov(in Chassidic thought) banished the remaining Shedim from this world, what would be the hava mina amongst Chassidim to continue a custom that contradicts their own belief? Nov 11, 2010 at 6:21
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    If the drinks were uncovered, wouldn't there be the problem of מים מגולין, which are outright forbidden because of danger (that a snake may have drunk from it and injected venom)? It is true that many posekim say that this doesn't apply nowadays since snakes are not commonly found in most places, but that would have been a consideration in Abaye's times.
    – Alex
    Nov 11, 2010 at 16:28
  • Re your second point - you're right, I don't know why we would keep this custom as compared to a lot of other shed-related ones that we don't.
    – Alex
    Nov 11, 2010 at 16:29
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    @mekubal: per Rambam, Hil. Rotze'ach Ushemiras Nefesh 11:11 (from Terumos 8:4 as explained in Chullin 10a), מים מגולין don't need to be left uncovered overnight to become forbidden; simply leaving them open long enough for "a snake to come out from under the handle of the container, drink, and go back into its hole" is enough.
    – Alex
    Nov 12, 2010 at 16:57
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    This is brought in Shulchan Aruch Harav as well, Hilchot Shmirot Guf V'Nefesh U'Bal Tashchit: chabadlibrary.org/books/default.aspx?furl=/adhaz/sh/sh6/12/1/4 - He says that this even applies these days.
    – Menachem
    May 13, 2012 at 1:12

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