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.