ANSWERS TO REVIEW QUESTIONS
prepared by Rabbi Eliezer Chrysler
Kollel Iyun Hadaf, Jerusalem
Previous dafEruvin 44
ERUVIN 42, 43, 44 sponsored by a generous grant from an anonymous donor. Kollel Iyun Hadaf is indebted to him for his encouragement and support and prays that Hashem will repay him in kind.
(a) Initially, we establish the Beraisa which forbids putting up a
Mechitzah of people, animals or vessels on Shabbos, standing up a bed and
draping a sheet over it to protect a corpse or food rays of the
sun - like Rebbi Eliezer, who forbids re-placing a skylight (a temporary
Mechitzah) on Shabbos and Yom-Tov; whereas Rav Nachman who permits making
a Mechitzah, holds like the Rabbanan, who permit it.
(b) Rav Nachman has support for this from a Beraisa - which permits the
placing of people to form a wall for one's Sucah, enabling one to eat etc.
in the Sucah, and to put up temporary walls as protection (in the same way
as the previous Beraisa forbade it).
(c) The Gemara rejects this explanation - on the grounds that the Rabbanan
of Rebbi Eliezer only permit *adding to* an existing Mechitzah, but not
*putting up a fresh one*.
(a) Rebbi Meir forbids the use of an animal as the wall for one's Sucah,
(because it may run away). Since it is not considered a wall, there is no
harm in placing it there (where it will serve as an Ohel - but not as a
Mechitzah). Note: The Gemara could have refuted this suggestion by
pointing out that the Beraisa (which we just established like Rebbi Meir),
permits eating and drinking etc. in the Sucah - suggesting that the animal
has the full Din of a Mechitzah. It is also not clear whether this answer
satisfactorily answers Rav Nachman (see Tosfos and Ritva).
(b) Rebbi Meir only invalidates an *animal* that is placed as a wall,
because it may run away, but who says that he also invalidates a person or
vessels (which the Beraisa with regard to Sucah also permits)?
(c) In addition, asks the Gemara, even if we establish the second Beraisa
like Rebbi Meir - he can only be following the opinion of the Rabbanan of
Rebbi Eliezer (since Rebbi Eliezer forbids even to add to an existing
wall), and the Rabbanan permit only *adding* to an existing wall, but not
putting one up from scratch, as we asked earlier.
(a) The Beraisa which permits putting up a wall of vessels - is speaking
about a Sucah which already has *three* Kasher walls, so that the fourth
wall of vessels is nothing more than an addition, which the Chachamim
permit. Whereas the Beraisa which forbids it, speaks about a Sucah with
only *two* walls, in which case, adding a third wall of vessels will
render the Sucah Kasher, and this the Rabbanan do not permit.
(b) The proof for this is Lashon 'Nafal Dofnah' (implying one of
the walls which rendered the Sucah Kasher) used by the first Beraisa,
which forbids using an animal - whereas the second Beraisa simply says
'Oseh Adam es Chavero Dofen' (which could just as well apply to the fourth
wall of the Sucah, which explains why it is Kasher).
(a) The Beraisa which permits making a wall of people to enable one to
eat, drink or sleep in one's Sucah - speaks when they are placed there
without prior knowledge that they have been placed as a Mechitzah; whereas
the Beraisa which forbids it, speaks when they know why they are there.
(b) Rav Chisda, who knew that the people were needed to form a Mechitzah -
did not actually form part of it.
(c) We cannot answer the discrepancy in a. by establishing the Beraisa
which permits it by the *fourth* wall - because with regard to a Mechitzah
of people, the Beraisa specifically mentions that it comes to permit
eating, drinking and sleeping in the Sucah - which can only be referring
to the *third* wall, which renders the Sucah Kasher, and not to the
*fourth* one, as we explained earlier.
(a) Shmuel gave lashes to those men who served as a Mechitzah (to enable
water to be brought in street), because they did so with the
knowledge that they were standing there as a Mechitzah.
(b) Some flasks belonging to Rava were lying in the street on Shabbos, so
the Shames took advantage of the throngs of people who came to hear his
Derashah to carry them into the house, using the people as Mechitzos. When
this happened a second time, and his Shames wanted to bring them in again,
Rava stopped him - because if people are used as Mechitzos too many times,
it is inevitable that eventually, they will realize why they are there,
and we have already learnt that people may only be used as Mechitzos as
long as they are not aware that they are being used as Mechitzos.
(a) Someone who left his Techum legally, only to discover that his journey
was unnecessary (for example if he left to testify that he had seen the
new moon, and then discovered that his testimony was not needed) - has two
thousand Amos from where he is, when he makes the discovery.
(b) Someone who leaves the Techum Shabbos to save his property from
robbers or from a river that was threatening to overflow and swamp his
field, or a midwife who left to deliver a baby - are all included in the
(a) Rabah explains 'Im Hayah be'Soch ha'Techum, Ke'ilu Lo Yatza' - to mean
that if he was still within his original Techum, he is permitted to return
to his house, and to revert to his original Techum, as if he had not left
his house in the first place.
(b) We might otherwise have explained it to mean that, once he left his
house, he has given up his original Techum, which now leaves him with no
Techum at all.
(c) Rav Shimi bar Chiya explains the Mishnah to mean - that, even if he
*has* left his original Techum, he is permitted to go back etc., provided
his current Techum overlaps his original one.
(d) Rabah holds that, once he leaves his Techum, he acquires Shevisah in
his new location, and we would not say in such a case that it is as if he
had not left his Techum. Nor does Rabah hold of the Neherda'i, who said
earlier (41b) that, once he re-enters his original Techum, he reverts to
(a) According to Rashi's second explanation - even Rabah speaks when he
has left his Techum; however, according to him, it is as if he had not
left his house, and he reverts to his original Techum, whereas according
to Rav Shimi bar Chiya, since the two Techumin overlap, they become like
one Techum, giving him a new Techum of almost eight thousand Amos,
incorporating his original two thousand Amos to the East of his original
residence (for example), and two thousand Amos to the west of his new one.
(b) Abaye asks Rabah from someone who acquired his residence in a cave of
four thousand Amos, whose roof was less than three thousand Amos, and
which had two entrances (like most caves did), one at either end of the
roof - did he not agree, he asked him, that one was able to walk the
entire three thousand Amos of the roof, plus two thousand Amos
one end of the roof, and two thousand Amos other, from which we
see that when two Techumin overlap, they do merge into one (like Rav Shimi
bar Chiya maintains).
(c) There is no proof re, Rabah counters - because that speaks
when he acquired his residence before Shabbos, which is why he acquires
both Techumin simultaneously; whereas in our case, when he only acquired
the one Techum before Shabbos entered, he cannot acquire the second Techum
on Shabbos, to combine with the first, only (if and when he does acquire
it) independently - at the expense of his original Techum.
(a) Abaye eventually proves Rabah wrong from Rebbi Eliezer, who (in a
Mishnah later in the Masechta) permits someone who left his Techum on
Shabbos to return, provided he is not more than two Amos outside the
Techum. - Now, he had not acquired those two Amos before Shabbos (as Rabah
considers necessary for one Techum to be absorbed inside another.
Nevertheless, Rebbi Eliezer considers the two Techumin that are outside
his original Techum to be absorbed in his original Techum - as if they
were one Techum - like Rav Shimi bar Chiya.
(b) Nor can Rabah answer that *that* is the opinion of Rebbi Eliezer, but
the Rabbanan argue (and he will hold like the Rabbanan) - because the
Rabbanan only argue about re-entering for a D'var Reshus, but for a D'var
Mitzvah, they agree with Rebbi Eliezer that one is permitted to return
two Amos outside the Techum.