Ohalos, Chapter 8, Mishnah 2. This chapter sorts objects into categories according to how they behave with regard to the tumah of a meis. Our mishnah continues the list of things that function as an ohel in both directions at once: they carry tumah to a person or to keilim that are underneath them together with a meis, and they also serve as a barrier, so that a person or keilim resting on top of them are protected from tumah lying beneath, and equally the reverse.
The list of the mishnah
"Hazizin": a ziz is a ledge. Some may recall the term from maseches Shabbos. The Bartenura defines it as "eitz o even yechidi," one single beam of wood or one single stone protruding out of a wall.
"Vehagizriyos": the reference here is to a veranda or balcony that extends outward from the face of a wall. Such a structure might be constructed of stone or of timber.
"Vehashovachos": these are the small compartments, something like little boxes set into a wall, built so that pigeons can fly in and out. People who raise pigeons construct them, and although the purpose is the birds, the structure itself forms an ohel.
The Tiferes Yisroel points out the chiddush in all of these items: none of them was built in order to shelter anything. A ledge, a balcony, a dovecote compartment: each was made so that something should rest upon it or inside it. Nevertheless, since in practice there is a covering with space beneath it, the halachah treats it as an ohel in every respect.
Shkifin and sloim
"Vehashkifin vehasloim." The Bartenura notes that these were already explained at the end of the third perek, so let us recall what we learned there. The perek closed with the view of Rebbi Yehuda, that any ohel not fashioned by human hands is not considered an ohel, "u'modeh," yet he concedes in the case of shkifin and sloim. These are rock formations that are hollowed out underneath, so that a person can walk beneath the stone. Shkifin refers to a hollow carved out by water; sloim refers to a rock that simply came out that way on its own. Even though no person shaped either of them, Rebbi Yehuda agrees that they carry the din of an ohel.
In connection with this, the well known account of Rebbi Akiva comes to mind. His initial reaction was that starting to learn was hopeless: at forty years of age, how could it possibly succeed? And in truth, the beginning was extremely difficult for him. I recall that my father, zichrono livrochoh, once learned this Chazal with me. I had come home and told him, "Tat, learning is so hard for me," and he sat down and went through this piece with me. Rebbi Akiva noticed a large boulder with a hole worn straight through it. What could possibly have produced that? One would assume some powerful drilling device. But the answer was water. Is water capable of piercing solid rock? It is, when it falls persistently, drop after drop, year after year, until the stone finally gives way. A person works the same way: persist, renew the effort again and again, and the siyata dishmaya arrives.
Returning to hilchos ohel, our mishnah teaches that the hollow of a rock counts as an ohel whether the water carved it out or whether it was formed that way naturally.
Goharim and shinnin
"Vehagoharim." The Bartenura explains the word as "min chor," a type of opening, "shemisham ba ha'or," through which light enters. As the Tiferes Yisroel presents it, this is the opening through which light comes into a cave, and there are ledges of rock above it.
"Vehashinnin" comes from the word shein, a tooth: the teeth of the rock. Picture a rock with a piece protruding from it like a tooth, and the projection forms an ohel in the space beneath it.
Sechachos and proyos
"Vehasechachos": here we have an ohel formed by branches. "Vehaproyos": the same idea, but formed by thorns.
The mishnah adds a condition to these: "shehein yecholim lekabel maziva rakah," that they are able to bear a thin layer of plaster. Maziva is the coat of plaster that is spread over a surface. If one would spread a thin coat of plaster on this covering and it would collapse through, then this is no roof at all, neither to hold tumah in nor to keep tumah out.
The natural question is why such a stipulation surfaces only at this point. For none of the items listed earlier did the mishnah insist that the covering be capable of supporting anything at all. The Rambam, at least as the Kessef Mishneh reads him, appears to hold that this condition is not confined to these last two cases but governs every item on the mishnah's list.
The mishnah then records a machlokes. According to Rebbi Meir it is enough that the covering be able to bear a thin coat of plaster, "vechachomim omrim" that a thin coat is not the measure: it must hold a "maziva beinonis," a middling layer of plaster, the sort that would be laid down for a floor. If it could carry only a maziva rakah, that is insufficient.
There is a second way to read this stipulation, and it accounts neatly for its appearing here rather than alongside the earlier items. We are dealing with branches, and branches inevitably leave gaps between them. In what sense is such a covering a roof at all? The measure for deciding whether the foliage is dense enough is whether a thin coat of plaster laid across it would stay put. Plaster does not need a leaf directly under every point, yet the branches have to sit close enough together to bear it. Rebbi Meir accordingly requires density sufficient for a thin coat, while the Chachomim require density sufficient for a heavier one. On this reading the question is not how strong the covering is, but how tightly spaced.
The mishnah defines its own terms
"Eilu hein hasechachos": having employed the terms sechachos and proyos, the mishnah now spells out what it intended by them. Sechachos is defined as "ilan shehu meisech al ha'aretz": the growth of a tree stretching out above the ground below. Meisech shares its root with schach, a covering. The Bartenura points to the language used of the keruvim above the Aron in Parshas Terumah, "sochechim bechanfeihem": their wings arched over to form a shelter. In just that way, a tree's leaves and branches arch above the earth underneath.
"Vehaproyos": these, as noted, are formed of thorns, specifically thornbushes jutting out above a wall. It was common practice to plant thorns along a wall's upper edge, perhaps as a deterrent to anyone thinking of climbing across. The growth, however, did not remain where it was planted. It pushed outward past the edge and hung down along the sides, until a genuine covering was created there. That is precisely the case our mishnah addresses. The term proyos derives from the language used of the nazir, whose hair was left to grow long, as the posuk states, "gadel pera se'ar rosho." That same pera denotes growth extending outward, which fits our explanation perfectly: the thorns were set at the wall's upper edge, yet they reached out beyond it and sagged downward to form this sort of ohel.
Summary
This is the closing list of items that serve as an ohel in both directions, to convey tumah and to block it:
- Ledges, whether a single stone or a single beam protruding from a wall, and full balconies
- Dovecote compartments built for pigeons to enter, which nevertheless form an ohel
- Hollowed rock formations, whether the water carved them or they came out that way naturally
- The "teeth" of rocks, where the stone takes a shape that creates an ohel, and the cave openings through which light enters
- Sechachos and proyos, an ohel formed of branches or of thorns, which according to Rebbi Meir must bear a thin coat of plaster (or, in the second approach, be closely enough spaced to support one), while the Chachomim require the measure of a middling coat
And the mishnah closed by spelling out its own vocabulary: sechachos, from "ilan shehu meisech al ha'aretz": the leaves and branches of a tree arching above the earth underneath; and proyos, thorns set at a wall's upper edge that push outward and sag down until a shelter is formed.