Rab Yehuda bar Ami quotes Rab Yehuda that a beit ha-peras that is
significantly trodden becomes clean, because no bone would remain that's as large as a barley corn.
Can the luz bone be destroyed by such physical pressure?
- Charles Stein
The Luz bone may be smaller than a Se'orah to start with.
Dov Zupnik
See Rashi on Breishis Raboh 28:3, see also Tos. D"H Tarnigoiles Bechoros 8a. (U'lhoi'r from Brochos 5b Dein Garmah, Luz is not mentioned in Rashi or Rashbam B"B 116a to answer Tumoh).
Derech Agav: According to the Rashi on the B"R it is possible that Rashi and the Riva hold the same (Tzarich Iyun that the Laz in Rashi here is different then either in Bchoirois 8a or Breishis 30:37 or Shoftim 1:24, while eve in the letter 3 they are not the exact same spelling). That would further be anchored according to Rashi Bamidbar 17:23 that the Shokeid grows the quickest .
The Vayikra Raboh mentioned in Rashi and Tos. is 18:1 both have the Girsa Vyinoeitz Hashokeid (Koheles 12:5 and Medrosh Raboh ibid) is the Luz not like in our prints (see Pirush Maharzu).
[In plain English: Rashi in his commentarry to Midrash Rabah Bereishis 28:3 writes that the name of the Luz stems from the nut of the same name, which is also known as the Shaked. It is called that name since it is the size of the Shaked. Tosfos in Bechoros 8a cites from the Riva that "Shaked" is an almond, and also relates the translation of the Luz bone to the Shaked based on the Vayikra Rabba. Rashi in Bechoros translates Luz as a different small nut ("kordla b'Laz," or hazelnut). Both of these nuts are presumably larger than a Se'orah -- and if so, the Luz bone should indeed be Metamei!]
Kol Tuv
Yitzchok Zirkind
SHALOM UVRACHA RABBI KORNEFELD
RE THE QUESTION ON THE LUZ - 3 EXPLAINATIONS OR NOT?
1) RASHI HERE AND RASHI IN ERUVIN 30B DB"TAHOAR"
2) SO MANY PEOPLE WALKED THERE THEY PUSHED ALL THE BROKEN BONES TO THE SIDE
THEREFORE CAN WALK THERE WITHOUT FEAR OF TUMA----RASHI GEMARA PESACHIM 92B
DEBUR MATCHILSHNIDASH AND LOOK RASHI NIDA 57 - DB SHNIDASH
3) BY TRAMPLING OF FEET THERE WOULD NOT BE ANY DUST THAT WOULD OTHERWISE COVER UP ESEM KESORAH; SO SAYS THE MEIRI IN MOED KATAN 5B
SEEMS TO ME RASHI HERE CAN GO LIKE POINT 2---
The third explanation does not seem to be consistent with the Gemara, for the Gemara says clearly that the reason is because "it is not possible for there to be a bone that has not been trampled underfoot." These words do not imply that the foot will expose the bone, but rather that the bone has become crushed by the feet walking over it (that is why the Gemara uses the word "Nidash," and not "Nidras").
For the same reason, the second explanation also does not seem to be consistent with the Gemara. When Rashi in Pesachim writes, "she'Derisas ha'Regalim He'evirum" ("the trampling of feet moved them away"), it seems that his intention (there and in Nidah) is to say what the Gemara here says -- that the feet moved them away by crushing them and making them too small to be Metamei.
Regarding the question about the bone of the Luz, it seems that since a Beis ha'Pras is only Asur mid'Rabanan, the Rabanan were lenient also in this regard, for perhaps the bone entered into the ground so deeply that it is not moved (Heset) by the feet that trample over it. The words, "It is impossible that a bone the size of a barley seed not be trampled underfoot," refer to the bones that were on the surface of the field and could be moved by walking upon them. Those that are beneath the surface of the field and that are not moved need no logical explanation to explain why they are not Metamei.
M. Kornfeld