6

Are there any issues with blowing on your glasses to clean e.g. dandruff off on shabbos? I was thinking that perhaps it is zoreh/winnowing - similar to blowing dust off old books?

In regards to zoreh applying to blowing dust off old books, I found it in the 39 Melachos book (Rabbi Dovid Ribiat) page 376:

It would also seem probable that the following examples are also forbidden under Zoreh:....Blowing dust off an old book, bookshelf or dusty bottle.

That quote itself is referenced to a footnote - the footnote itself does not cite an exact source for that specific example, but explains why it should apply by citing many similar examples (e.g. where even blowing via mouth and not natural wind is Zoreh), and also gives rishonim sources mentioning that zoreh also applies to dust.

  • IIRC the Rov in Johannesburg, Rav Yaakov Salzer zt"l frowned upon this behavior. It's a dim 5 decade old memory. – Danny Schoemann Aug 28 '17 at 8:52
  • Gabriel, welcome to Mi Yodeya. Your question can be greatly strengthened by supporting your assertion that one may not blow dust off old books. I am not sure that this would be universally prohibited. If it were, many people attending older shuls might not be able to daven well on Shabbat and Yom Tov. – DanF Aug 28 '17 at 13:10
  • Sure @DanF - found it in the 39 Melachos book (Rabbi Dovid Ribiat) page 376: 'It would also seem probable that the following examples are also forbidden under Zoreh:....Blowing dust off an old book, bookshelf or dusty bottle." That quote itself is referenced to a footnote - the footnote itself does not cite an exact source for that specific example, but explains why it should apply by citing many similar examples (e.g. where even blowing via mouth and not natural wind is Zoreh), and also gives rishonim sources mentioning that zoreh also applies to dust. – Gabriel Aug 29 '17 at 11:34
  • Thanks. You should probably copy / paste this info into your question so that it is more visible. I think I have this book at home, so I'll see if I can study that area. Offhand, this sounds like a questionable area similar to the discussion as to whether one may use spray cans (esp. spray canned "whipped" cream) on Shabbat. Some say no, others say yes. – DanF Aug 29 '17 at 13:14
  • 2
    Note that this definition of zoreh goes against the Bavli, basically all the Rishonim, the Shulhan Arukh, Rabbi Akiva Eiger, Mishna Berurah, Arokh HaShulhan... – mevaqesh Aug 29 '17 at 23:16
4

R. Moshe Stern (Be'er Moshe 6:62) explicitly permits one to clean glasses on Shabbos, by both blowing on and wiping the glasses. He does not cite the Rema's ruling (OC 319:17) in which he finds spitting [into the wind] liable of winnowing. R. Binyamin Zilber too (Az Nidbaru vol. 13, no. 14) permits the above case and likewise does not discuss winnowing. My assumption for their seeming disregard of the Rema is simply because, as noted by @mevaqesh, most authorities do not agree with this ruling.

R. Ephraim Greenblatt (Rivevos Ephraim 3:310) has a responsum where he too permits cleaning the glasses with a cloth and does not even mention an issue of winnowing. Same goes for Yalkut Yosef (Shabbos, vol. 2 pg. 88).

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .