Siman - Shabbos Daf 39

  • Toldos hachama

Rav Nachman clarified the machlokes in the Mishna between R’ Yose and the Rabbonim regarding cooking from unconventional sources of heat:

- All agree that cooking directly from the heat of the sun is permissible.

Rashi explains that cooking from the sun is not דרך בישול, the way of cooking, and people will not confuse it with regular cooking.

- All agree that cooking from תולדות האור (derivatives from the heat) such as the heat of the kettle is prohibited, since it is considered בישול מדאורייתא, Biblically forbidden cooking.

- They disagree with regards to cooking from תולדות החמה, cooking from derivatives of the sun, such as a scarf heated by the sun:

o  The Rabbonim decreed that תולדות החמה is prohibited because people might be confused and come to cook with תולדות האור. Ex. If one can cook from a scarf heated by the sun, they might come to cook from a scarf heated by a fire.

o  R’ Yose does not forbid תולדות החמה because of תולדות האור.

  • Cooking an egg in the sand or dust

The Gemara asks why R’ Yose does not permit cooking an egg in the sand or dust that was heated by the sun, if in general he permits תולדות החמה.

- Rabbah says that R’ Yose concedes here because   גזרה שמא יטמין ברמץ, there was a decree enacted out of concern one will come to conclude that it is permissible to also insulate food with hot ash.

- Rav Yosef says that when one buries the food in the sand they will come to move the dirt and, according to Rashi, they will transgress the melocho of choreish, (plowing).

  • The halachah follows the mediator

It was said in the name of Rebbe, כל מקום שאתה מוצא שנים חלוקין ואחד מכריע הלכה כדברי המכריע -  whenever you have two Tannaim who disagree and a third one mediates between them, the halacha follows the opinion of the mediator.