Keilim 6:4-7:1

Keilim 6:4

Let’s say that two stones were made into a stove and they were rendered ritually impure. If one placed a stone on the outer side of this one and another stone on the outer side of that one, then inner half of each of the middle stones remains unclean but the outer half of the inner stones is ritually clean. If the ritually clean outer stones are removed, the original middle stones revert to their previous state of impurity.

Keilim 7:1

Let’s say that the fire basket (a type of small stove) of a homeowner lost a piece. If the part lost was smaller than three handbreadths, the fire basket remains susceptible to ritual impurity because one could light a fire below and a pot would still boil above. If the fire basket was reduced more than this, it is no longer susceptible to ritual impurity. If one put a stone or gravel into the diminished fire basket, it remains insusceptible but if one coated it with clay, then it is susceptible to impurity from that point on. This was Rabbi Yehuda’s response to the question of an oven that was placed over the mouth of a pit or a well (in mishna 5:6).