Ohalos, Chapter 9, Mishnah 16. Much of this chapter has been occupied with a beehive (caveras) and the question of when a vessel standing over tumah blocks it, when it lets the tumah pierce straight up and down, and when it becomes an ohel of its own. Our mishnah returns to that very same set of questions, but the object under discussion is no longer a beehive. Here we are dealing with a barrel (chavis) of earthenware, and, as the mishnah itself will tell us at the end, a barrel that is not capable of receiving tumah at all.
That statement needs a moment of clarification, because at first hearing it sounds impossible. Cheres, after all, does become tamei; the inside of a kli cheres is precisely the classic case of a vessel that contracts tumah. The answer, which the mishnah spells out in its closing clause, is that the potter here shaped the barrel and gave it its form, but never fired it in the kiln. Until the earthenware has been hardened in the kivshan, the vessel is not yet a kli for purposes of tumah. So the entire opening portion of the mishnah is speaking about a barrel that simply cannot become tamei.
The barrel standing upright
Our mishnah opens with the words "Chavis shehi yeshevah al shuleha," a barrel seated on its base. It stands the way a barrel normally stands, upright, with its mouth pointed toward the heavens. The mishnah adds that it is "ba'avir": positioned out in the open, so that a person standing beside it and lifting his eyes sees nothing overhead but sky. We will also learn, as the mishnah unfolds, that it sits flush on the ground, with no tefach of space separating it from the earth beneath.
The Bartenura describes for us what these barrels looked like, and the picture is essential for understanding the whole mishnah. The barrel was narrow at the top, where the opening was, then bulged out widely at its middle on both sides, and then tapered somewhat again toward the bottom. Think of the small jugs that held the shemen zayis, the kind that come alongside a menorah or that you have seen pictured: narrow mouth, wide bulging belly, narrowing base. That is the chavis of our mishnah, standing upright in the open air.
"U'kezayis min hameis nasun tachteha": a kezayis of a meis, according to the Rambam's reading, has been placed underneath the barrel. "O b'socha keneged kurkurasa": or the kezayis is inside the barrel, lying on its floor. The word kurkurasa comes from the language of karka, the ground or floor, and the point is that the kezayis is resting on the barrel's floor at its center. Shine a laser beam upward from that kezayis and it would travel straight out through the narrow opening at the top. Or, put differently, if you stood over the barrel and peered in, you would be looking directly down at the kezayis.
Whichever of these two positions the kezayis occupies, underneath the vessel or centered on its floor with the mouth straight above it, the ruling is identical: "tumah boka'as v'olah, boka'as v'yoredes." Piercing upward, the tumah exits through the narrow mouth and continues into the space overhead; piercing downward, it passes beneath the barrel into the ground below. Whatever kli happens to occupy that vertical shaft, higher up or lower down, contracts tumah, while a kli set off to a side stays tahor. We already met this rule earlier in the chapter regarding a caveras resting on its base: an intact vessel with tumah beneath it, where the tumah traveled up and down along one straight column.
Next come the words "v'hachavis temei'ah." On the surface the mishnah is declaring the barrel itself tamei, which is impossible here, since this barrel is of a type that cannot take on tumah at all. The meaning must therefore be that vessels sitting inside the chavis, where the tumah passes, become tamei. Beyond a kli placed on top of the barrel and aligned with the kezayis, even a kli lodged within the barrel along that same upward course is rendered tamei. The chavis gives it no shelter. Being a vessel rather than an ohel, it neither absorbs tumah nor holds it back, and the reason is plain: nothing roofs it over. All that lies above it is its own gaping mouth.
The tumah beneath the bulge, from outside
The mishnah moves on to a kezayis positioned "tachas dafnah mibachutz." Now the tumah is found not under the barrel's base but under the swelling of its side wall, and on the outer side of it. Here too the mishnah rules "tumah boka'as v'olah": the tumah drives upward through the curving wall, so that a kli resting above that swelling, level with the kezayis, becomes tamei. And "u'voka'as v'yoredes": reverse the picture, with the kezayis lying upon the outer curve of the wall, and the tumah presses downward to render tamei a kli lying beneath it. The outward curve of the wall is no barrier.
To this the mishnah adds "v'hachavis tehorah." Since the tumah here sits neither below the base nor at the middle of the floor but rather under the curve of the wall, the contents of the chavis stay tahor, including a kli that happens to occupy the hollow of that very curve, straight across from the kezayis. In this arrangement the barrel does shield what it holds. We have seen the identical halachah with a caveras lying on its side: the tumah bypasses the beehive and affects only whatever stands in a straight column above or below, while the interior is safe, since the beehive there possessed a floor below and a covering above. The same holds for the swelling of our barrel: the region under the curve has, functionally, a base and a roof, so that anything resting inside there is protected.
The tumah inside the bulge
The mishnah now inverts the picture: "b'socha v'tachas dafnah." Word for word, the kezayis lies within the vessel and under its wall. The case is a kezayis set down inside the barrel, though not in the middle: it rests off to a side, in the region where the barrel swells. Were it in the center, the mouth and not the wall would be what stands above it. Since it occupies the widened part, picture yourself crawling in and turning your gaze upward from that spot: what you would see is wall, because the side pushes outward and then bends back inward again over your head. That is what tachas dafnah conveys.
At this point the mishnah requires us to measure: "Im yesh b'dafnos posei'ach tefach." Should the hollow formed by the swelling walls contain the space of a tefach, meaning a cubic tefach, a tefach in height by a tefach in length by a tefach in width, then "hakol tamei": the tumah takes hold everywhere, in the vessel's interior, in the space above and in the space beneath. A bulge of such dimensions is quite large, yet the halachah follows directly, for a cavity of that size constitutes an ohel by itself, and an ohel carries the tumah through the entire barrel.
One place is excluded: "u'cheneged piha" stays tahor. Anything situated opposite the barrel's mouth is unaffected, for the ohel reaches no further than that point. The column of space lying right below the open mouth has nothing roofing it, and it therefore belongs to no ohel whatsoever.
"V'im lav": where the swelling falls short of that measure and no cubic tefach is to be found within it, the kezayis lying there has the status of tumah retzutza, tumah pressed in with no ohel over it. In that event the mishnah returns to "tumah boka'as v'olah, boka'as v'yoredes": upward it climbs and conveys tumah to whatever is overhead, downward it descends and conveys tumah to a kli under the curve of the wall, but only to objects standing squarely opposite the kezayis.
Which barrel are we speaking about?
The mishnah now asks: "Bameh devarim amurim? B'tahorah." All of the above applies to a barrel that is tahor. Taken at face value that means only that the barrel happens to be clean, but the Bartenura explains that far more is intended: it is a barrel of the kind that cannot become tamei, an earthenware vessel that never underwent firing. As we learned in Maseches Keilim, a kli cheres becomes susceptible to tumah only once it has been hardened in the kiln, nitzrefah b'kivshan. Until that final stage of manufacture, the vessel does not receive tumah at all.
Yet notice the parallel to the caveras. There the beehive was tahor because it held forty se'ah and was therefore too large to be a kli that receives tumah, and nevertheless, being a functioning vessel, it retained enough of a connection to tumah that it could not block tumah unless it constituted an ohel. Precisely the same is true of our chavis that cannot become tamei: it does not receive tumah, but it does not stop tumah either, unless it forms an ohel.
"Aval im haysah temei'ah": the picture changes when we are dealing with a barrel that is able to take on tumah, one that the potter finished and then baked in the oven in the ordinary way of pottery, so that it now counts as mekabel tumah. Alternatively, "o gevohah min ha'aretz" by a tefach: even a barrel that cannot receive tumah, never having been placed in the kivshan, but which is elevated a full tefach off the ground instead of sitting flat upon it, so that the gap underneath becomes an ohel. Or "o mechusah": a lid has been laid across the top, turning the whole stretch from rim to rim into an ohel. Or "o kfuyah al piha": the barrel has been flipped over, mouth downward, so that a person looking at it from above sees its base and its bulging flanks, while the opening lies pressed against the floor.
Throughout this entire group of scenarios, a kezayis of tumah situated "tachteha," below the barrel, or "o b'socha," within its interior, or "o al gabah," resting upon its outer surface, produces the ruling "hakol tamei": everything located in any one of those three places contracts tumah.
The difference between the first case and the last three
These four scenarios are not, however, all alike. Take the first, where the chavis is itself mekabel tumah because the potter brought it to completion and baked it in the furnace (not incinerated, obviously, but fired as required so that the clay hardens, and from that moment it ranks as a kli). Such a barrel itself contracts tumas meis, and once it has, every item inside it turns tamei automatically, regardless of whether it happens to stand opposite the kezayis, because the entire cavity of a kli cheres becomes tamei. Something placed on the barrel's exterior top, by contrast, becomes tamei only when it is keneged hakezayis, since there the tumah merely shoots up in a column and touches nothing but what lies within that column.
The three remaining scenarios work differently. A barrel lifted a tefach from the ground, a barrel sealed with a lid, a barrel resting upside down on its mouth: each of these gives us a true ohel, since the raised barrel has a roofed pocket of a tefach beneath it, the lid forms a ceiling over the interior, and the inverted barrel has no upward opening whatsoever. In one respect these are handled more stringently than the barrel that is susceptible to tumah. The tumah occupies the full extent of the space under the ohel, and from that whole space it ascends and descends, conveying tumah even to items outside the barrel that never stood opposite the kezayis. Where an ohel exists, we stop thinking in terms of a single vertical shaft: the tumah first extends laterally throughout the covered area, and only afterward travels upward and downward.
Reviewing the mishnah
A chavis of cheres that cannot receive tumah, because it was shaped but never fired, is sitting upright on its base in the open air, resting on the ground, its mouth facing the sky. A kezayis of a meis lies beneath it, or inside it on its floor directly under the mouth: the tumah pierces upward and downward, rendering tamei whatever lies in its path above or below, and keilim inside the barrel in that path as well, for the barrel has no roof and cannot shield them.
The kezayis lies outside, beneath the bulge of the wall: the tumah pierces up through the bulge, and if it lies above the bulge it pierces down, but what is inside the barrel in that region is protected, since there it has both a floor and a ceiling.
The kezayis lies inside the barrel, within the bulging part beneath the wall: if that space holds a cubic tefach it is an ohel, and everything in the barrel is tamei even off the line of the tumah, except what lies opposite the mouth. If it does not hold a tefach, the tumah is retzutza and pierces only straight up and straight down.
Everything set out until now concerns a barrel that cannot take on tumah. When the barrel is mekabel tumah, or is held a tefach above the ground, or has a lid over it, or lies upside down, then tumah below it, within it or upon it makes every item in those locations tamei. Here a distinction applies: a barrel that is itself mekabel tumah imparts tumah to its whole interior, while outside it only objects aligned with the kezayis are affected; an ohel, by contrast, carries the tumah sideways first and then up and down, so that even beyond the barrel a kli turns tamei although it never stood opposite the source of the tumah.