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Eruvin 35

1) BREAKING DOWN A WOODEN "MIGDAL" ON SHABBOS

QUESTION: According to Rabah and Rav Yosef, the Migdal of the Mishnah (34b) is one made of wood. The Gemara at first suggests that the argument in the Mishnah is whether this Migdal is considered a utensil ("Kli"), in which case it is permitted to break down on Shabbos, or whether it is considered a building ("Ohel"), in which case it is forbidden to break down on Shabbos (because of "Soser Binyan").

What does the Gemara mean? If the Migdal has a capacity of forty Se'ah, it is certainly an Ohel. If it does not hold forty Se'ah, it is certainly a Kli. In what case could there be an argument whether it is considered an Ohel or a Kli? What type of Migdal is the Mishnah discussing?

ANSWERS:

(a) TOSFOS RABEINU PERETZ explains that the Mishnah is discussing a Migdal that holds forty Se'ah. However, since it is something that is often moved around even when it is full, therefore there is an argument whether it is considered an Ohel or a Kli. The Gemara then asks that there is no source for creating such an argument; the discussion in Zavim is revolving in a different point entirely.

(b) TOSFOS HA'ROSH and the RITVA also explain that the Mishnah is discussing a vessel that holds forty Se'ah. However, they assert that such a Kli indeed cannot be Mekabel Tum'ah. The opinion that says that it *can* become Tamei is not talking about the vessel itself, but the Kelim that are inside of it. If a Zav causes a vessel that is weak and easily shaken to vibrate, it is as if the Zav directly shook the contents of that vessel, and they are Tamei.

That is why the Mishnah discusses *Heset* and not Maga. It is referring to shaking the items inside the vessel by shaking the vessel, which is done by Heset and not be Maga.

The Gemara assumes that the type of vessel that is so heavy that a Zav who shakes it is not Metamei what is inside of it is not considered a vessel (but rather an Ohel) with regard to Shabbos.

35b

QUESTION: The Mishnah mentions a case of an Eruv made with Terumah food that became Tamei, but it is uncertain whether the food became Tamei before nightfall (in which case the Eruv would be invalid) or after nightfall (and the Eruv is valid). Rebbi Meir and Rebbi Yosi argue whether such an uncertain Eruv is valid or not. Rebbi Meir maintains that an Eruv in doubt is *not* a valid Eruv. The Gemara asks how can Rebbi Meir be stringent regarding an Eruv in doubt, when elsewhere we find that he is lenient in a case of doubt (in a case where one is in doubt whether the body that one touched at night was living or dead at the time that he touched it).

The Gemara answers that the case of the Eruv that became Tamei is when it is known for sure that the Terumah became Tamei at the beginning of Bein ha'Shemashos (that is, a Sheretz fell on it at that time).

If so, asks the Gemara, why does Rebbi Yosi say that the Eruv is valid? The Gemara is forced to retract its suggestion that the case is when the Terumah became Tamei at the beginning of Bein ha'Shemashos.

Why did the Gemara not suggest a simpler answer, asks REBBI AKIVA EIGER (Gilyon ha'Shas). TOSFOS in Shabbos (34a, DH Sheneihem) explains that a Chezkas Taharah is effective only in a case when one is not sure when an item became Tamei (for example, before or after Bein ha'Shemashos). If, however, it is known for certain that the item became Tamei during Bein ha'Shemashos, but we are not sure whether Bein ha'Shemashos is day or night, then we *cannot* use the Chazakah to determine that the item is Tahor until the night. A Chazakah can only tell us that an item retains its status quo until the latest possible moment (that is, until the moment at which there is no longer any doubt about its status). Since, in the case of an item becoming Tamei during Bein ha'Shemashos, we know *exactly when* the item became Tamei, and the only doubt is whether that point in time was considered day or night, the Chazakah does not tell us that it is day and the food is Tahor.

If so, the Gemara should have said that Rebbi Meir will admit that the food is Tamei in the case of the Mishnah because it is discussing a case where we know that the Sheretz fell onto it during Bein ha'Shemashos, rendering it Tamei. A Chazakah cannot tell us whether the given moment during Bein ha'Shemashos when the Sheretz fell on the Terumah is day or night. In such a case, Rebbi Yosi should still say that it is a valid Eruv because he maintains that any Eruv in doubt is valid. Why did the Gemara not suggest such a case?

ANSWERS:

(a) RASHI (Shabbos 34a) seems to disagree with Tosfos's rule. Rashi maintains that a Chazakah could be applied even in such a case. Even though we know exactly when the Sheretz fell on the Terumah, the Chazakah can tell us that that moment during Bein ha'Shemashos was Halachically nighttime and not daytime (and the Eruv is thus valid), since night is inherently later than day. According to Rashi, then, the Gemara was not able to suggest that this is the case in which Rebbi Meir and Rebbi Yosi argue, because in such a case Rebbi Meir would agree that it is a valid Eruv because of the Chazakah.

(b) The RESHASH points out that from Berachos 2a it seems that Rebbi Meir and Rebbi Yosi are of the opinion that the duration of Bein ha'Shemashos is not more than "k'Heref Ayin," the blink of an eye. If so, it may be suggested that we cannot be in doubt because the Sheretz fell during Bein ha'Shemashos. If Bein ha'Shemashos is the length of the blink of an eye, the Sheretz cannot fall exactly at that moment. That is why the Gemara cannot say that the argument is when the Sheretz fell at exactly that moment.

(c) Perhaps when the Gemara says that there was a Sheretz on the Terumah at the beginning of Bein ha'Shemashos, it means to say exactly what Rebbi Akiva Eiger suggests that the Gemara should say. Furthermore, our Gemara is probably the source for Tosfos suggestion that a Chazakah does not apply when the it is known that the Sheretz fell on the Terumah during Bein ha'Shemashos. Tosfos learned that the Gemara is suggesting that the argument in our Mishnah involves Rebbi Akiva Eiger's case, when the Sheretz fell on the Terumah at a known point during Bein ha'Shemashos. If this is the Gemara's case, then why does the Gemara ask that Rebbi Yosi should agree that the Eruv is not valid? Since Chazakah does not apply in this case, there should remain a Safek (whether the moment at which the Sheretz fell on the Terumah is considered day or night), and Rebbi Yosi rules that a Safek Eruv is valid!

The RASHASH explains that Rebbi Yosi indeed would not permit a Safek Eruv in such a case. The Gemara concludes (36a) that according to Rebbi Yosi an Eruv in doubt is valid only because of a Chazakah. (This is also clear from Tosfos, ibid., DH Sheneihem). Without a Chazakah, Rebbi Yosi would not permit use of the Eruv; therefore the case of the Mishnah cannot be that a Sheretz fell on the Terumah during a known point of Bein ha'Shemashos.