Study Shabbat folio 51B with parallel Hebrew-English text, traditional commentary, and modern study tools. Free access to Babylonian Talmud online.
he may not remove the pot and then return it to its place.
R' Yehuda says: The chaff of fine flax is like manure. Therefore, one may not insulate food in it even on Friday.
One may place a copper urn upon a copper urn, and one may place an earthenware pot upon an earthenware pot because the lower utensil will not heat the upper one. However, one may not place an earthenware pot upon a copper urn, or a copper urn upon an earthenware pot, as in that case there is conce
And just as one may not insulate hot food to keep it warm, so too, one may not insulate cold food to keep it cold. R' Yehuda HaNasi permitted insulating cold food on Shabbat.
And one may neither crush snow nor hail on Shabbat so that its water will flow and he will be able to drink it. That act involves creation of a new entity, water from ice, on Shabbat, which is prohibited. However, he may place the snow or the hail into a cup or a dish and allow it to melt on its own