An oven: Its beginning is four [handbreadths] and its remnants are four [handbreadths, these are] the words of R’ Meir. But the Sages say: When do these words apply? In [the case of] a large [oven], but in [the case of] a small [oven], its beginning is the smallest amount and its remnants are the majority of it. [The above applies] from the time its manufacture is complete. What is [considered] the completion of its manufacture? From when one heats it enough to bake sponge cakes in it. R’ Yehudah says: When one heats a new [oven] enough to bake sponge cakes in an old [oven].

A stove: Its beginning is three [fingerbreadths] and its remnants are three [fingerbreadths], from the time its manufacture is completed. What is [considered] the completion of its manufacture? From when one heats it enough to cook on it the most easily cooked egg, [which has been] beaten and put into a stewpot. A kupach: [If] one made it for baking, its measure is that of an oven; [if] one made it for cooking, its measure is that of a stove. A stone that juts out one handbreadth from an oven, or three fingerbreadths from a stove, [is] a connection. [A stone] that juts out of a kupach: [If] one made it for baking, its measure is that of an oven; [if] one made it for cooking, its measure is that of a stove. R’ Yehudah said: They only said ‘‘one handbreadth’’ between the oven and the wall. [If] two ovens were adjacent to each other, one handbreadth is allotted to one [oven] and one handbreadth to the other [oven], and the remainder is tahor.

The rim of a stove is tahor. The enclosure of an oven: When it is four handbreadths high it contracts tumah via contact and airspace, [but] less than this is tahor. If it was connected to [the oven], even on three stones, it is tamei. The flask receptacle and the spice receptacle and the lamp receptacle of a stove contract tumah via contact but do not contract tumah via airspace, [these are] the words of R’ Meir. R’ Yishmael rules [them] tahor.

An oven that was heated from the outside, or that was heated without his intent, or that was heated in the artisan’s workshop, is tamei. It once happened that a fire broke out among the ovens of Kefar Signah, and the case came to Yavneh, and Rabban Gamliel ruled [the ovens] tamei.

The supplement of the oven of householders is tahor, but that of bakers is tamei, because he supports the spit on it. R’ Yochanan HaSandlar says: Because he bakes with it when he is hard pressed. Similarly, the supplement of the cauldron of olive boilers is tamei, but that of dyers is tahor.

An oven that was filled with earth up to its midpoint: [The area] from the earth and downward contracts tumah via contact; [the area] from the earth and upward contracts tumah via airspace. [If] one placed [an oven] over the mouth of a pit or over the mouth of a cistern and placed a stone there, R’ Yehudah says: If he lights [a fire] below and [the oven] is heated above, it is tamei. But the Sages say: Since in any event [the oven] was heated, it is tamei.

An oven that contracted tumah, how is it rendered tahor? One divides it into three [sections] and scrapes off the [clay] coating down to the ground. R’ Meir says: It is not necessary to scrape off the [clay] coating nor [is it necessary to divide it] down to the ground; rather, one reduces it from within [to less than] four handbreadths. R’ Shimon says: And it must be moved. [If] one divided it into two [sections], one large and one small, the larger [section] is tamei and the smaller [section] is tahor. [If] one divided it into three [sections], [such that] one [section] was as large as [the other] two, the larger one is tamei and the two smaller ones are tahor.

[If] one cut [the oven into] segments along its width, [each segment that is] less than four handbreadths is tahor. [If] one plastered it with clay, it becomes susceptible to tumah from when he heats it enough to bake sponge cakes in it. [If] one distanced the [clay] coating from it and placed sand or pebbles between them, of such [an oven] they said: A niddah and a woman who is tahor may bake in it and it is tahor.

An oven that came in pieces from the artisan’s workshop, and he made hoops for it, when he puts them on [the oven] it is [still] tahor [and then] it is tamei. [If] he removed its hoops, it is tahor. [If] he returned [the hoops] to [the oven] it is tahor. [If] he plastered it with clay it becomes susceptible to tumah, and he need not heat it, since it was already heated.

[If] one cut [the oven into] segments and placed sand between the segments, R’ Eliezer rules [it] tahor, but the Sages rule [it] tamei; this is the oven of the [coiled] serpent. Arabian cauldrons that one digs in the ground and plasters with clay: If the clay can stand on its own, it is tamei, but if not, it is tahor; and this is the oven of Ben Dinai.

An oven of stone or of metal is tahor, but [the metal oven] is tamei as a metal utensil. [If] it developed a hole [or] became damaged [or] cracked [and] one made a [clay] coating for it or a supplement of clay, it is tamei. How large must the hole be? [Large] enough for the flame to pass through. And the same applies to a stove. A stove of stone or of metal is tahor, but [the metal stove] is tamei as a metal utensil. [If] it developed a hole [or] became damaged [or] cracked [and] one made feet for it, it is tamei. If one plastered it with clay, whether on the inside or on the outside, it is tahor. R’ Yehudah says: On the inside it is tamei, but on the outside it is tahor.