Ohalos, Chapter 11, Mishnah 8. Throughout this perek we have been examining houses that contain a hollow space beneath the floor, and the recurring issue is whether that sunken space counts as shut off from the room or as part of it. The mishnah before us paints an elaborate scene: a plastered cistern inside a house, a menorah standing down in it, and a basket resting overhead. We must work out how far the tumah of the house extends.
The mishnah begins, "hachodesh shebabayis", the chodesh that is in the house. Chodesh and dus are two names for one and the same structure, and it pays to recall a distinction drawn earlier. A bor is merely a cavity excavated in the earth. A dus is fashioned by hand: its sides are built up with masonry and plastered over so that water will stay in. Our subject, then, is a man-made cistern located inside a dwelling.
"Vehamenorah besochoi", and a menorah stands within it. Why would a menorah be down inside a cistern? Perhaps someone lowered himself in to look for something and took a lamp along for light. Whatever the reason, there it stands, and it is taller than the depth of the pit: "vehaperach shela yotzei", its blossom emerges. A menorah of this design consists of several slender branches, each topped by a lamp; the lamp does not sit on the branch itself but upon an ornamental blossom, and it is that blossom which clears the level of the floor of the house.
The scene still needs one more detail. "Uchefisheh nesunoh alov", and a kefisheh is set upon it. A kefisheh is the oversized basket in which olives are packed and left to soften. It sits on the projecting blossom, teetering there. Yet its placement matters: "she'im tinotol hamenorah, uchefisheh omedes al pi hachodesh", were one to pull the menorah out, the basket would not tumble in. Its width is such that it would come to rest on the sides of the cistern and stay put at the level of the floor. Into this house tumah now enters.
The dispute of Beis Shammai and Beis Hillel
"Beis Shammai omrim hachodesh tohor", Beis Shammai say the chodesh is tahor, meaning that the keilim lying at the bottom of the cistern escape the tumah of the house. "Vehamenorah tmeiah", the menorah, however, contracts tumah. What decides the matter for them is the exposed section: the blossom clears the floor, and air surrounds it on every side, in the gap between it and the edge of the dus, with the basket above. Since that portion stands out in the air of the room, tumah reaches it and the menorah turns tamei.
"Beis Hillel omrim af hamenorah tehoroh", Beis Hillel say the menorah too stays tahor. Its bulk, the greater part of the keli, lies inside the dus, and a utensil is judged by its principal portion; once that portion is shielded, no part of the menorah becomes tamei.
Where both schools agree
"Umoideem", both schools acknowledge a second scenario. "she'im tinotol hamenorah uchefisheh nofeles", were the basket so narrow that pulling the menorah out would let it slip past the sides and drop to the bottom, then "hakol tamei", nothing is spared. The governing rule is that an item held up by a keli cannot function as a chatzitzah against tumah. In that scenario the basket genuinely rests upon the menorah, so it closes off nothing whatsoever.
Our mishnah's basket, by contrast, is not truly dependent on the keli. The menorah stands beneath it, but even without the menorah the basket would hold its position over the mouth of the pit. And as was taught previously, a kefisheh of these dimensions is not mekabel tumah, and such a keli is capable of combining with the sides of an ohel to bar the tumah from passing. That is precisely the role it plays here.
Hence the single point left in dispute is the little projecting piece of the menorah that rises out of the dus. Beis Shammai treat it as lying outside the seal; Beis Hillel treat it as included, since most of the menorah is within, and so the entire utensil remains tahor. All of this, though, presumes a basket wide enough to hold itself up over the opening of the pit. Should it be narrow enough to fall through, both schools agree that it provides no shielding at all, not for the menorah and not for the vessels below.
What sort of tumah is in the house?
The Bartenura asks what sort of tumah we are dealing with in this house. If a meis lies there, we run up against the halachah of cherev harei hu kechalal: a keli that touches a corpse acquires the corpse's own status and becomes an avi avos hatumah. Imagine, then, that our menorah had absorbed tumas meis in this fashion and turned into an avi avos hatumah. It would be as though the meis itself were positioned inside the dus; the basket above would roof it over, and everything in the pit would instantly be tamei.
The Bartenura therefore explains that the house in the mishnah contains no meis. What it contains is a keli that had touched a meis, and the halachah is that a keli touching such a keli drops a level and is only an av hatumah, not the equivalent of the corpse. On that basis the vessels below can remain tahor.
The Rambam reads it otherwise, maintaining that the mishnah works even with an actual meis in the house. To his mind, cherev harei hu kechalal, whereby a keli touching corpse tumah is given the very status of the corpse, is limited to a keli in direct contact with the meis. Our menorah touches nothing; it is merely under one ohel together with the meis. In such circumstances the menorah is not elevated to the level of an avi avos hatumah, and the ruling of the mishnah holds as stated.