ANSWERS TO REVIEW QUESTIONS
prepared by Rabbi Eliezer Chrysler
Kollel Iyun Hadaf, Jerusalem
Previous dafEruvin 4
ERUVIN 4 - dedicated to the memory of Sarah Dvosya bas Rav
Mordechai (Feldman) of Milwaukee by her children.
(a) No! Rava is not saying that the Amos of a Sucah, a Mavoy and of Kil'ayim
are the same. According to him, the Amos of a Sucah and a Mavoy consist of
six tight Tefachim, and that of Kil'ayim, of six loose Tefachim - both
Lechumra (like Abaye).
(b) Abaye tries to establish the Beraisa: 'Kol Amos she'Amru Chachamim
be'Amah bas Shishah, u'Vilevad she'Lo Yehu Mechuvanos' - by Amos of Kil'ayim
(c) This answer however, is unacceptable - because Raban Shimon ben Gamliel
goes on to say 'Kol Amos she'Amru Chachamim be'Kil'ayim, be'Amah bas
Shishah, u'Vilevad she'Lo Yihyu Metzumtamos'; from which we can deduce that
the Tana Kama is speaking about *all* Amos (i.e. those of Sucah and Mavoy,
(d) Abaye answers - that seeing as Raban Shimon ben Gamliel voices his
opinion, he follows the opinion of Raban Shimon ben Gamliel.
(a) According to Rava, Raban Shimon ben Gamliel's main Chidush - is that the
Amah of Kil'ayim should not be measured tightly, and the reason that he adds
'be'Amah bas Shishah' - is not to exclude the Amos of Sucah and Mavuy, but
to exclude the Amah of the Yesod of the Mizbei'ach, and that of the Sovev
(the base and the ledge around which the Kohanim could walk, respectively),
which consisted of *five* Tefachim, rather than *six*.
(b) "ve'Eleh Midos ha'Mizbei'ach be'Amos, Amah, Amah ve'Tefach, ve'Cheik
ha'Amah", according to Rashi's final explanation, means that, even though
all the measurements of the Mizbei'ach consist of one Amah (of five
Tefachim) plus a Tefach, the Amah of the Yesod will consist of just an Amah.
(c) It was the height of the Yesod that was a small Amah; the width was a
(a) Both the Amah width and the Amah height of the four Keranos - consisted
of small (five-Tefachim) Amos.
Also the Amah square of the Mizbei'ach ha'Zahav (the small incense-Altar)
consisted of a small Amah of five Tefachim.
(b) A Zeres is half an Amah. Consequently, when the Pasuk gives the width of
the Keranos as being a Zeres - it is referring to the measurement of the
Keranos from the middle, one Zeres in each direction.
1. If someone enters a house which has Tzara'as, holding clothes or rings in
his hands, he and the clothes become Tamei immediately. Not so the clothes
and the ornaments that he is wearing - they only become Tamei if he waits in
the house the amount of time it would take to eat an Achilas Peras (four
egg-volumes) of wheat-bread with condiments, whilst he is leaning (each of
these details diminishes the time of eating).
(b) In fact, the Shiurim are 'Halachah le'Moshe mi'Sinai', but the Rabbanan
found support for them in this Pasuk (not that we actually learn the Shiurim
2. The bone of a corpse is Metamei - by touching and by carrying (but not by
Ohel) if it is the size of a barley.
3. The Shiur of the pits and the skin of grapes that a Nazir needs to eat in
order to be Chayav (Malkus) - is a Revi'is (of a Lug = one and a half egg-
volumes) of wine (which is thicker than water, and therefore has more
surface tension than water.
4. The Shiur for carrying on Shabbos as regards food is that of a
'ki'Gerogeres' (a dried fig).
5. Wooden vessels which break, no longer receive Tum'ah. People still tend
to use a vessel with a hole up to the size of a pomegranate, for which
reason it will still receive Tum'ah. Once it is the size of a pomegranate
however, the owner throws it away, and it no longer receives Tum'ah. (These
Dinim are confined to the vessels of private people, not to vessels that are
sold in shops, where they tend to discard all broken vessels, however small
6. The Shiur of most things is a Kezayis. The list includes Cheilev, blood,
Nosar and Pigul.
7. The Shiur for which one is Chayav Kares on Yom Kipur is that of a Koseves
(a) We learn from ...
1. ... "ve'Rachatz es Kol *Besaro"* - that nothing may interrupt between the
water and the skin (known as a Chatzitzah) when one Tovels.
(b) Rabah bar Rav Huna said - that one knotted hair is a Chatzitzah, three
is not, whereas two was a Safek by him.
2. ... "ba'Mayim" - that one must Tovel in a collection of water (a Mikveh),
though not necessarily in spring water.
3. ... "ve'Rachatz es *Kol Besaro*" - that there must be sufficient water in
the Mikveh for an average person to Tovel (one Amah by one Amah by three
Amos = forty Sa'ah).
4. ... "*es* Kol Besaro" - that knotted hair is also a Chatzitzah (as will
be explained immediately).
(c) When Rav said that Chatzitzin are 'Halachah le'Moshe mi'Sinai' - he was
referring to Rav Yitzchak, who said (with referrence to hair - see Tosfos Dh
'Devar Torah') 'Devar Torah (i.e. ' Halachah le'Moshe mi'Sinai') Rubo
u'Makpid Alav, Chotzetz, ve'she'Eino Makpid Alav, Eino Chotzetz'.
(d) The Rabbanan decreed - by Rubo she'Eino Makpid and by Mi'uto ha'Makpid.
(e) The Rabbanan did not decree on Mi'uto she'Eino Makpid because of Mi'uto
ha'Makpid or because of Rubo she'Eino Makpid - because that would be a
Gezeirah li'Gezeirah, which the Rabbanan do not usually do?
(a) Chazal have said that Hashem did not descend lower than ten Tefachim,
from which we see that above ten Tefachim is considered a different Reshus.
Now the Aron, from whose lid Hashem spoke to Moshe, was nine Tefachim high,
which, together with the one Tefach of the lid, makes ten Tefachim. So we
see that ten Tefachim constitutes a Mechitzah.
(b) Rav says that Mechitzin is Halachah etc. - according to the opinion of
Rebbi Yehudah, in whose opinion the Amos of the Aron (and of all the holy
vessels) were Amos of *five* Tefachim, and not of *six* (which means that
the Aron was not ten Tefachim tall, but eight and a half). Consequently,
Mechutzin can indeed be 'Halachah le'Moshe mi'Sinai'.
(c) According to Rebbi Meir (who learns Mechitzin from the Aron), the
Halachah by Mechitzin was said by 'Gud', 'Levud' and 'Dofen Akumah': 'Gud'
means that we sometimes stretch a wall upwards ('Gud Acheis Mechitzasah') or
downwards ('Gud Asek Mechitzasah') - as if it reached the ceiling or the
floor, even though, in reality, it does *not*; 'Levud' means that whenever
there is a space of less than three Tefachim, we extend the wall to the end
as if it was filled in; 'Dofen Akumah', which is confined strictly to the
Dinim of Sucah, means that we permit Pasul Sechach between the Sechach and
the wall of the Sucah as if the wall of the Sucah was bent (which is no
reason to invalidate the Sucah).
(a) In the case of a Koreh which is higher than twenty Amos, one could of
course, simply lower the Koreh. However, it would probably be easier to
raise the level of the ground, by piling up earth across the width of the
Mavuy (which is the option discussed by the Gemara).
According to the Gemara's final interpretation of Abaye - Abaye agrees with
Rav Yosef that a Koreh serves as a Heker, and that even a Heker from
underneath ought to suffice. However, he decrees that one Tefach is not
sufficient, because people might tread down the earth to a point where the
Koreh will once again be more than twenty Amos high. And since one Tefach is
not enough, he requires four Tefachim, which is considered a significant
measurement in other places.
(b) According to Abaye, one would need to fill in earth for four Tefachim
along the Mavuy.
(c) The Gemara initially explains that Rav Yosef permits carrying under the
Koreh (because it is the *outer* edge of the Koreh which is considered to be
extended to the ground). Consequently, one Tefach (the Tefach underneath the
Koreh) will suffice; whereas Abaye forbids it (because, according to him ,
it is the *inner* edge that is considered to be extended) That is why four
Tefachim (a significant measurement) is required.
(d) Abaye (in the first alternative answer) requires four Tefachim -
because, according to him, a Koreh does not serve as a Heker, but as a
Mechitzah. In fact, he too agrees that it is the *outer* edge that is
'extended'. However, a Mechitzah must serve a Reshus of at least four
Tefachim, which is why he requires piling up the earth for a length of four