Ohalos, Chapter 18, Mishnah 4. Until now the chapter has dealt with two kinds of beis hapras: a field in which a kever was ploughed over, and a field in which a meis was lost. Our mishnah introduces a third case that carries the name beis hapras, and then returns to the ploughed field to ask a practical question: when someone has already walked across such a field, can we examine the ground and clear him?
The third beis hapras: sdei bochim
The mishnah's third type is "sdei bochim," a field of weeping. Bochim comes from crying, and this is the spot where the funeral procession would halt: the mittah was set down, the mourners gathered and wept, and afterwards the mittah was carried onward to the burial place. The Bartenura points out that this location is a "mokom rochok mibeis hakevaros," a place at some distance from the cemetery itself.
Notice at once that there is no real concern of tumah here at all. The mittah was rested on the ground and then lifted and taken away; nothing was buried and nothing was left behind. Why then does the mishnah group it together with the other cases? Because a few of the halachos that govern a beis hapras apply to it as well, and on that account it earns the same title.
Lo yitaas velo yizroas
The mishnah rules: "lo yitaas," one does not plant trees in a sdei bochim, "velo yizroas," and one does not sow seeds there. What is the basis of this restriction, if no tumah is involved?
The source of the prohibition lies in an entirely different corner of Shas. Grant that the owner never formally designated this patch as a public stopping place for levayos; even so, by now he has surely written off any hope of reclaiming it for his own use. That produces the halachah known as meitzar shehechziku bo rabim, ground of which the tzibbur has taken hold. Whoever has studied the relevant sugyos in Bava Basra will recall the discussion of a lane that the many have made into their thoroughfare: once the rabim hold it, the owner may no longer plant trees or grain in it, nor may he ruin it in any way, since the public depends on it for needs of their own. Our sdei bochim is no different. The ban on planting, then, has nothing whatever to do with tumah and taharah; it belongs to the world of Bava Basra, protecting what the rabim have taken for themselves.
All of this holds only where "nisyaashu mimenu habaalim," where the owners gave up hope of recovering the land. If, however, people simply eye somebody else's field and decide that it would make a convenient sdei bochim, and the owner objects and refuses to allow it, they do not acquire their sdei bochim. The field remains his field. Everything depends on whether he protested from the outset or whether he abandoned his claim.
The earth itself is tahor
The mishnah continues: "va'afarah tahor," its soil is tahor. There is no kever in this ground and no reason to suspect one. And the mishnah goes further: "ve'osin mimena tanurim lekodesh," one may even take earth from this field and use it to fashion an oven in which basar kodoshim will be cooked. This is precisely where the sdei bochim parts company with the first two types of beis hapras. Earth taken from a field where a kever was ploughed over, or from a sadeh she'avad boh kever, may not be used to build an oven that will serve for hekdesh. Here it may.
Bodkin for the korban pesach, not for terumah
At this point the mishnah turns to a fresh topic. As the Bartenura notes, everything until now concerned the sdei bochim; from here the mishnah takes us back to the case with which the chapter opened, a field in which a kever was ploughed under.
The wording is: "u'modim Beis Shammai u'Beis Hillel shebodkin le'osei pesach." Both yeshivos concur that a bedikah is made on behalf of one who is coming to offer his korban pesach. Picture the situation: a Yid is travelling to shecht his pesach, he is questioned about the road he took, he recounts his route, and it emerges that a beis hapras lay along the way. He is beside himself: what will become of his korban pesach? For his sake a special examination of the soil is carried out, and the mishnah will presently set out how. Should the search yield nothing, not so much as an etzem k'seorah, a bone no larger than a barleycorn, he is cleared to go ahead with his korban.
But "ve'ein bodkin l'terumah." A kohen is about to sit down to his terumah, and he is told that he too walked through a beis hapras. He asks that the field be checked for him. Here we do not perform the bedikah. What is the difference between the two?
Failure to bring the korban pesach carries a chiyuv kares. True enough, if we were to hold him back on account of a safek tumah he would not actually be liable to kares, yet the very severity of the punishment shows us how grave a matter it is to be left without a korban pesach. Since the tumah of a beis hapras is only miderabbanon to begin with, Chazal were prepared to rely on a special bedikah rather than let their own gezeirah stand in the way of a korban pesach. For a kohen and his terumah there is no such emergency. Eating terumah is indeed a mitzvah, an aseh, but preventing an aseh is simply not on the same level of gravity as blocking a man from offering his korban pesach, where in essence failure carries kares. So we tell him: Reb Kohen, if you wish to eat terumah, go be metaher yourself.
The nozir: a machlokes
The point at issue is "u'lenozir," a nozir who has crossed a field where a kever was ploughed over. It remains unknown to us whether tumah reached him from an etzem k'seorah lying in that ground. Should it have, his neziros collapses: he shaves, brings his korbanos, and counts afresh from day one.
"Beis Shammai omrim bodkin." To spare him all of that and allow him to continue his neziros, we examine the field; if no etzem k'seorah is found, we tell him to carry on. "U'Veis Hillel omrim ein bodkin." Even were we to search and find nothing, we would tell him: Reb Nozir, you must shave, bring the korbanos, and start your neziros over from the beginning.
Read in this way, it is Beis Hillel who take the harder line, which is out of the ordinary, and there are indeed those who hold that the two names ought to be switched, so that Beis Shammai are the ones who refuse a bedikah for the nozir while Beis Hillel permit it. In any event the picture is straightforward: where a korban pesach hangs in the balance an examination is unquestionably made, where terumah is involved we do not lean on an examination at all, and in the case of the nozir the two yeshivos are divided.
Keitzad hu bodeik
Now comes the question "keitzad hu bodeik," in what manner is this check performed? "Meivi es he'afar," he takes the earth, "sheyachol l'asiso," that is, the loosened soil that can be lifted and worked with, "ve'nosno l'sokh kvarah," and pours it into a sieve, "shenekaveha dakin," one perforated with tiny holes. The openings must be narrow enough that an etzem k'seorah, which is really quite small, cannot slip through them. "U'memachech": the lumps of soil left sitting on the sieve are then rubbed apart by hand. "Im nimtza sham etzem k'seorah" - should such a bone come to light, the ruling is tamei, and the man who hoped to offer his pesach is told that he may not. Should the soil turn up nothing, the ruling is tahor.
A question from Mesechtas Pesachim
Anyone who has learned Mesechtas Pesachim may find a difficulty here. There the Gemara discusses a person who must cross a beis hapras in order to bring his korban pesach, and prescribes something entirely different: he blows. As he advances he blows at the loose earth and looks to see whether a bone is exposed. That is a completely different form of bedikah from the one in our mishnah.
One approach distinguishes between the two situations. The Gemara in Pesachim deals with a man who comes to ask beforehand: I must reach Yerushalayim, this is my route, and it passes through a beis hapras, what shall I do? To him we give the method of blowing, and the details of how it works belong to that sugya. Our mishnah in Mesechtas Ohalos speaks of one who has already crossed, and now asks whether he may still offer his korban pesach. For that we have the bedikah of the sieve.
Certain rishonim read our mishnah quite differently from the Bartenura. To their mind, "keitzad hu bodeik" is not spoken about the traveller who has already gone through the field and is worried about his pesach, since for him there is the method of blowing. The mishnah is rather laying out one of the ways in which a beis hapras can itself be brought to taharah, a theme the coming mishnayos go on to develop. The question would then read: a beis hapras belongs to me and I wish to render it tahor, how do I proceed? And the answer is that the loosened soil is sifted through a sieve with fine holes.
Summary
The mishnah opened with a third heading that carries the name beis hapras: the sdei bochim, the field of tears, where the mittah was set down and the levayah stood and wept. Planting is forbidden there, trees as much as crops, since the place has been handed over to that use; once the din of meitzar shehechziku bo rabim attaches to it, the owner cannot wake up one morning and announce that this is his field and he has thought better of it. That holds only where he wrote it off; had he objected at the outset, the field stays entirely in his hands. The soil itself, though, is tahor, since no meis lies buried in it, and it may even be shaped into ovens for hekdesh. From there the mishnah turned back to the ploughed field: an examination is made for one who must offer his korban pesach, whose omission carries kares for a meizid, but not for a kohen who wishes to eat his terumah, for eating terumah, mitzvah though it is, involves no emergency. Where a nozir wants to know whether tumah reached him and his neziros must start over, Beis Shammai and Beis Hillel are at odds. And the examination itself: the loosened earth is emptied into a sieve with fine holes, so that whatever drops through is known to hold no etzem k'seorah, while the clods remaining above are crumbled by hand. If it comes out clean, the one bringing the pesach may go ahead, and according to some shittos the nozir is treated in the same fashion.