Keilim 5:3-4

Keilim 5:3

The “crown” around the hole on a stove is not susceptible to ritual impurity. The tray around the oven when four handbreadths high (about a foot) is susceptible to ritual impurity through touching and through its airspace; less than this, it is not susceptible. If he connected an undersized rim to an oven, even if it’s only propped up by stones on one side, then it is susceptible to ritual impurity. Rabbi Meir says that the compartments for the oil, the spices and the lamp that are in the stove are susceptible to ritual impurity through touching but not through the stove’s airspace; Rabbi Yishmael says they are not susceptible.

Keilim 5:4

Let’s say that an oven was not yet fired, completing its construction. If it was heated from the outside, unintentionally or in the builder’s home, it becomes susceptible to ritual impurity. It once happened that a fire broke out among never-fired ovens in Kfar Signa, heating them. The question was brought to the Sages in Yavne and Rabban Gamliel ruled that the ovens were susceptible to ritual impurity.