Pesachim, Chapter 7, Mishnah 2. Here we continue the discussion of roasting the Pesach offering: in which vessels and in what manner the roasting is valid, and the status of meat that was roasted by a heat other than the heat of the fire.
The vessels in which the Pesach may not be roasted:
"Ein tzolin es haPesach lo al hashafud" - one may not roast the Pesach offering on a metal spit. In the previous mishnah we dealt with a wooden spit, whereas here the reference is to a metal spit: the metal itself becomes hot, and so the Pesach ends up being cooked by the heat of the spit rather than by the heat of the fire.
"V'lo al ha'askalah" - one may also not roast it on a metal sheet; an iron sheet is what is called an askalah.
The Gemara adds here a line that is missing from the wording of the mishnah, by way of chisurei michsera (the text is incomplete): "Im askalah menukeves - sharya" - that is, if the sheet is perforated with holes that allow the fire to pass through it, this is a valid way of roasting the Pesach offering.
"Amar Rabbi Tzadok: ma'aseh b'Rabban Gamliel she'amar l'Tavi avdo: tzei utzleh lanu es haPesach al ha'askalah" - Tavi, Rabban Gamliel's servant, is mentioned several times in the mishnayos. Here too the case is one of a perforated sheet, on which roasting is valid.
Three rulings concerning meat roasted by a heat other than the heat of the fire:
"Naga b'charso shel tanur - yiklof es mekomo" - if the meat of the Pesach itself touched the earthenware of the oven, a problem arises: that spot was roasted by the heat of the earthenware and is invalid, since it was roasted by the heat of the oven rather than by the heat of the fire. Therefore that spot must be peeled off and discarded.
"Nataf mirotbo al hacheres v'chazar alav - yitol es mekomo" - if some of the gravy dripped onto the earthenware of the oven and then splattered back onto the offering, removing a thin peel alone is not enough; rather, one must remove a portion that has some thickness to it, the width of a person's thumb, because gravy tends to penetrate deep inside.
"Nataf mirotbo al hasoles - yikmotz es mekomo" - fine flour was lying in the oven and had been heated by the fire inside it (a practice we would not follow today, out of concern that it might become chametz, though evidently they knew how to control the situation). If gravy from the Pesach dripped onto the hot flour, the gravy was roasted also by the heat of the flour and not by the heat of the fire alone, and it becomes forbidden to eat. Therefore one scoops up a handful of the flour where the gravy fell and removes it, and the rest of the flour is permitted to be eaten.
In summary: a single principle underlies all the rulings of this mishnah - the Pesach offering must be roasted by the heat of the fire alone, and not by the heat of anything else: not by the heat of a metal spit, not by an unperforated sheet, not by the earthenware of the oven and not by hot flour. And wherever it was roasted by another heat, that part must be removed: peeling where the meat touched the earthenware, removing a thumb's width of thickness where gravy splattered back from the earthenware, and scooping out a handful of the flour that absorbed the gravy.