Today’s daf discusses the classic case of a mesokhria d’nazyata – the cloth stopper of a barrel – that cannot be used to close a wine barrel on Yom Tov. The prohibition stems from the fact that when the stopper is tightened it will invariably squeeze out some of the liquid, and squeezing liquid out of cloth is forbidden on Shabbat and Yom Tov.
Although it is taken for granted that squeezing liquid out of cloth is forbidden on Shabbat, the exact source of this prohibition is unclear. It appears that sohet (squeezing) is most likely a toladah – a derivative – of one of the 39 activities forbidden on Shabbat, specifically:
- dash (threshing), or mefarek, which involves removing desirable contents from a peel or covering that is unnecessary or unwanted,
- melaben (whitening), when squeezing out the liquid is part of a washing process, or
- tzove’ah (coloring), when squeezing out the liquid leaves the cloth a different color.
The Sho’el U’meishiv suggests an interesting proof that the prohibition on squeezing is not derived from mefarek. The case presented in our Gemara refers specifically to the activity being performed on Yom Tov, when, unlike on Shabbat, activities done for the purpose of food preparation are permitted. Thus the prohibition must stem from either melaben or tzove’ah.
The Arukh presents an entirely different approach to this Gemara, one that is apparently a tradition dating back to the time of the ge’onim. According to this approach, the mesokhria d’nazyata is not a cloth stopper, but a wooden piece that acts as a cover to an opening in the side of the wine barrel. Thus, the concern is not one of squeezing, but rather an issue of possible boneh – building. For all that the individual’s intent is to keep the wine from leaking out of the barrel, nevertheless by securing the cover on the barrel, he is effectively completing the side of the barrel, which would be forbidden on Shabbat and Yom Tov.