that one may even return it, doing so is permitted even on Shabbat and not only on Shabbat eve. And Rav Oshaya also holds: One may even return it even on Shabbat. As Rav Oshaya said: Once we were standing on Shabbat before Rabbi Ḥiyya the Great and we passed up to him a kettle [kumkemos] of hot water from the bottom floor [deyota] to the top floor, and we poured him a cup and returned the kettle to its place on top of the stove, and he did not say anything to us. Apparently, he is of the opinion that even on Shabbat it is permitted to return a pot to the stove.

Rabbi Zerika said that Rabbi Abba said that Rabbi Tadai said: They only taught that it is permitted to return vessels with the food inside them when they are still in his hand; however, if he already placed them on the ground, he obviously regretted placing them on the fire and it is prohibited to replace them on the stove. Rabbi Ami said: That which Rabbi Tadai did and said, he did on his own, and not in accordance with the accepted halakha. Rather, Rabbi Ḥiyya said that Rabbi Yoḥanan said as follows: Even if one placed the pot on the ground, it is permitted to return it to the stove.

The Gemara remarks that Rav Dimi and Rav Shmuel bar Yehuda disagreed about this matter, and both stated their opinion in the name of Rabbi Elazar. One said that when they are still in his hand, it is permitted to return them to the stove; when they were already placed on the ground, it is prohibited to do so. And one said that even if one placed them on the ground, it is also permitted to return it to the stove. Ḥizkiya said in the name of Abaye: That which you said, that when it is still in his hand, it is permitted to return it to the stove; we only said that halakha when his original intention was to return it to the stove. However, when it was not his original intention to return it, and he reconsidered and decided to return it, it is prohibited to return it. This proves by inference that if one placed it on the ground, even if his intention was to return it, it is prohibited.

Some say a different version of what Ḥizkiya said in the name of Abaye: That which you said, if one placed it on the ground it is prohibited; we only said that halakha when it was not his original intention to return it. However, if his original intention was to return it, it is permitted. This proves by inference that while they are still in his hand, even if it was not his original intention to return it, it is permitted. With regard to this matter, Rabbi Yirmeya raised a dilemma: In a case where he neither placed them on the floor nor held them in his hand, but he hung them on a stick, what is the ruling? In a case where he placed it on top of a bed, what is the ruling? Similarly, Rav Ashi raised a dilemma: If one transferred them from one urn to another urn what is the ruling? The Gemara said: These dilemmas stand unresolved.

MISHNA: The halakhot that were stated with regard to a stove were specific to a stove’s unique structure and the manner in which it retains heat. However, with regard to other baking apparatuses, i.e., an oven or a kupaḥ, there are different rules. The mishna delineates: An oven that they lit even with straw or rakings, one may neither place a pot inside it nor atop it on Shabbat. Whereas a kupaḥ that was lit with straw or rakings, its legal status is like that of a stove, and one is permitted to place a pot atop it on Shabbat. If it were lit with pomace or with wood, its legal status is like that of an oven and it is prohibited to place a pot atop it on Shabbat.

GEMARA: With regard to that which we learned in the mishna that an oven that they lit even with straw or rakings, one may neither place a pot atop it nor inside it, Rav Yosef thought to say that when the mishna says inside it, it means actually inside it; and when it says atop it, it means actually atop it. However, to lean a pot against an oven, it may well be done. Abaye raised an objection to Rav Yosef from that which we learned in our mishna: A kupaḥ that was lit with straw or rakings, its legal status is like that of a stove. If it were lit with pomace or with wood, its legal status is like that of an oven, and it is prohibited. By inference: If it were like a stove, it would be permitted. With what circumstances are we dealing? If you say that he placed the pot atop the kupaḥ, and in what case? If you say it is referring to a case where it is not swept and covered with ashes; a stove that is not swept and covered with ashes, is it permitted even to place a pot atop it on Shabbat? Rather, isn’t it referring to a case where one seeks to lean a pot against a kupaḥ, and it taught: It is like an oven, and prohibited?

Rav Adda bar Ahava said: Here we are dealing with the cases of a kupaḥ that is swept and covered with ashes and an oven that is swept and covered with ashes, and the mishna is to be understood as follows: It is like an oven in the sense that, although it is swept and covered with ashes, it is prohibited to place a pot atop it; as, if its legal status were like that of a stove, when it is swept and covered it may well be done. The Gemara comments that there is a baraita that taught in accordance with the opinion of Abaye: An oven that one lit with straw and with rakings, one may not lean a pot against it, and needless to say one may not place a pot atop it, and needless to say one may not place a pot inside it, and, needless to say if it was lit with pomace or with wood it is prohibited. While with regard to a kupaḥ that was lit with straw or with rakings, one may lean a pot against it, but he may not place a pot atop it. If it was lit with pomace or with wood, one may not lean a pot against it.

Rav Aha, son of Rava, said to Rav Ashi: This kupaḥ, what are its circumstances? If it is considered like a stove, even if it was lit with pomace or with wood, it should also be permitted. And if it is considered like an oven, even with straw or with rakings, it should also not be permitted. Rav Ashi said to him: From a halakhic perspective, a kupaḥ has intermediate status. Its heat is greater than that of a stove; however, its heat is less than that of an oven.

The Gemara asks: What are the circumstances of a kupaḥ? What are the circumstances of a stove in terms of the configuration of the vessels? Rabbi Yosei bar Ḥanina said: A kupaḥ is a small vessel that is similar to a stove; however, it only has one hole with enough space to place a single pot. A stove is like a double kupaḥ with enough space to place two pots. Abaye said, and some say that Rabbi Yirmeya said: We also learned this matter in a mishna dealing with the laws of ritual purity and impurity: An impure stove that was divided lengthwise is pure because it can no longer be considered a vessel. It is a broken vessel, and a broken vessel cannot become ritually impure. However, if the stove was divided widthwise, between the spaces for the pots, then it remains impure because it became two small stoves. However, a kupaḥ, whether it was divided lengthwise or whether it was divided widthwise, is pure because it can no longer be used as there is no way to put even a single pot on it. That is the difference between a kupaḥ and a stove.

MISHNA: In addition to the halakhot that deal with cooking on the fire on Shabbat, several related halakhot are discussed. The mishna says: One may not place a raw egg next to an urn full of hot water so that it will roast slightly. And one may not even wrap it in cloths, i.e., one may not heat the egg inside cloths that were heated in the sun. And Rabbi Yosei permits doing so in that case. And, similarly, one may not insulate it in sand or in road dust that was heated in the sun so that it will roast. Although there is no actual cooking with fire here, it is similar to cooking and the Sages issued a decree to prohibit doing so.

The mishna relates a story about the people of the city of Tiberias, and they ran a cold-water pipe [silon] through a canal of hot water from the Tiberias hot springs. They thought that by doing so, they could heat the cold potable water on Shabbat. The Rabbis said to them: If the water passed through on Shabbat, its legal status is like that of hot water that was heated on Shabbat, and the water is prohibited both for bathing and for drinking. And if the water passed through on a Festival, then it is prohibited for bathing but permitted for drinking. On Festivals, one is even permitted to boil water on actual fire for the purposes of eating and drinking.

GEMARA: A dilemma was raised before the Sages: One who violated the halakha in the mishna and slightly roasted an egg next to an urn, what is the ruling? Rav Yosef said: One who slightly cooked an egg is liable to bring a sin-offering, as he performed the act of cooking on Shabbat, which is prohibited by Torah law. Mar, son of Ravina, said: We also learned something similar in the mishna: