ANSWERS TO REVIEW QUESTIONS
prepared by Rabbi Eliezer Chrysler
Kollel Iyun Hadaf, Jerusalem
Previous dafEruvin 48
(a) (Rebbi Chiya's version of) the Beraisa that so amused Rebbi Yossi
b'Rebbi Chanina stated that fish-nets (in the form of a wall of reeds)
placed between two Techumei Shabbos of two cities (whose borders met in
the water) were not sufficient to divide the water between the two cities,
and that consequently, no-one from either city was permitted to draw water
from the river (because the water from each one's Techum mixed with the
water of the other), unless they put up a metal wall.
(b) Rebbi Yossi b'Rebbi Chanina's amusement cannot have been due to ...
1. ... the fact that the Beraisa followed the opinion of Rebbi Yochanan
ben Nuri (who holds Cheftzei Hefker Konin Shevisah), whilst he held like
the Rabbanan. Is it because Rebbi Yossi b'Rebbi Chanina holds like the
Rabbanan, that Rebbi Chiya is obligated to do likewise?
(c) Rebbi Yossi b'Rebbi Chanina laughed - because all this is not
necessary. Chazal were lenient by water, and permitted even a suspended
Mechitzah (which does not even reach the water), as if it was a proper
2. ... another Beraisa, which gives the water of a flowing river or of a
fountain the Techum of whoever collects it - because maybe that speaks
about water that is still (e.g. the water in a lake), but not water in a
river - that is moving.
3. ... the fact that Rebbi Chiya required a metal wall (in other words, he
laughed because, just as a wall made of fish-nets was futile because it
allowed the water to pass, so would a metal wall be futile - for the same
reason) because maybe what the Beraisa was saying was that even a metal
wall would be ineffective.
(a) The Chachamim in our Mishnah, who say that someone who slept during
Bein Hashemashos has only four Amos - mean four Amos in all directions (a
total of eight Amos square); whereas Rebbi Yehudah, who says 'le'Eizeh
Ru'ach she'Yirtzeh, Yelech' - only gives him four Amos, either in the one
direction, or two Amos in each direction from the point where he is
(b) Although the Rabbanan permit him to walk *eight* Amos, he is permitted
to carry only *four*.
(c) According to Rebbi Yehudah, the extra Amah the Torah gives to each
person -to enable him to take an object from below his feet and place it
above his head.
(d) According to Rebbi Meir - the four Amos are large ones (i.e. slightly
more than four ordinary Amos, since one needs more than an Amah to
stretch), whereas according to Rebbi Yehudah, the four Amos are exact.
(a) The four Amos of which we are speaking - could mean four Amos measured
by each individual's arm-length, or it could mean the fixed Amah that was
used in the Beis ha'Mikdash (and which consisted of six average Tefachim).
(b) If we were to learn like the first explanation - then a giant would
have more space to carry than an ordinary person (a leniency which the
Torah is unlikely to have given him. A small person would have *less*,
which would not present a problem, because that would entail a Chumra.
(c) Even if we were to learn that everyone's four Amos consisted of their
own arm-length, the fact that the Mishnah in Kelim does not include this
case in the list of 'ha'Kol Le'fi Mah she'Hu Adam' would not bother us -
because that rule is not absolute in this case: because, in any event, an
ordinary-size person with small arms, will have four regular-size Amos
(like the four Amos in the Beis ha'Mikdash), and not those measured by his
(a) By comparing the case of the three men, where the middle man's Techum
partially overlaps the Techumin of the outer ones, to three courtyards,
where the outer two open into the Reshus ha'Rabim, and which made an Eruv
with the courtyard in the middle, but not with each other - Rebbi Shimon
was asking the Chachamim why it was that they argued with him in the
latter case, where they forbade all three courtyards to carry in each
other's courtyard (even in the courtyard with whom they had made an Eruv -
unless all *three* combined with an Eruv), they agreed with him in the
former (that each of the outer two were permitted to carry in the middle
one's two Amos and vice-versa.
(b) The Chachamim replied - that they agreed with him in the former case,
because there were only three *individual* people involved, sufficiently
few to expect them to be careful (th at the two outer ones would not carry
from one to the other); whereas in the latter case, which deals with three
*groups* of people, they issued a decree, forbidding even the members of
the courtyards who *had* made an Eruv with each other, to make use of it,
just in case some of the residents would forget and come to carry from one
of the outer courtyards to the other.
(c) The fact that the two outer courtyards combined to make an Eruv with
the middle one, will not help to make the three Chatzeros into one, says
Rav Yehudah - because it speaks when it was the middle courtyard which
placed the Eruv into the two outer ones (and not vice-versa, as we thought
(d) Rav Sheshes concedes that, had the outer two courtyards placed their
Eruv in the middle one in *one* room, then all three would be considered
as one courtyard, so that they would all be permitted to carry in all the
courtyards. However, the Mishnah speaks when they placed their Eruv (even)
in the middle courtyard, but in *two* rooms (one courtyard in one, and the
other, in the other).
Beis Hillel holds that an Eruv placed in two vessels in one room is valid
- because it was placed in *the same* room, but if it was divided and
placed in two *
different* rooms, they may well agree that the Eruv is Pasul, like Rav
(a) If the members of the middle courtyard placed their Eruv in the two
outer ones, asks Rav Acha B'rei de'Rav Ivya on Rav Yehudah, then, the
moment they made an Eruv with *one* of the outer courtyards, they merge as
if they were *one* courtyard. In that case, when the same courtyard went
on to make an Eruv with the second outer courtyard, why are they not also
the Sheluchim of the courtyard with whom they merged, in which case the
two outer courtyards should now have merge too - to be able to carry in
each other's domain (as if they had made their own Eruv).
According to Rav, the Rabbanan hold that, wherever they placed the Eruv -
the outer courtyards (who made an Eruv with the middle one) are permitted
to carry in the middle courtyard, but not the middle one with the outer
ones, since each of the outer courtyards draws the middle one to it, and
its residents cannot be residents in two courtyards which did not make an
Eruv with each other (i.e. each courtyard prevents the middle one from
carrying in the other one).
(b) Not so, says Rav Ashi. Because from the fact that the two outer
courtyards made an Eruv with the middle one and not with each other, it is
clear that each outer courtyard does not want the middle one, to act as
its Sheli'ach in that regard.
(c) Rav Acha B'rei de'Rav Ivya also has a problem with Rav Sheshes - since
the two outer courtyards placed their Eruv in the middle one, according to
him, it should be considered as if they were all living in the middle
courtyard, and since the two pouter courtyards placed their Eruvin in two
different rooms, they clearly did not make an Eruv with each other.
Consequently, they should all be forbidden to carry anywhere in the
courtyard, even in the middle section - like five people, four of whom
made an Eruv, when the fifth failed to participate, in which case the one
who failed to participate forbids the other four to carry in the entire
(d) In the case of the five residents of the courtyard, the reason that
the one forbids all the others, is because he too, resides in the
courtyard; whereas, in our case, the two residents of the two outer
courtyards do not really reside in the middle one. There, they will only
combine to *permit* carrying from one courtyard to the other, but not to
*forbid* doing so.
(a) In fact, even Shmuel agrees with the previous statement, forbidding
the *middle* courtyard to carry in the two outer ones. The Rabbanan
however, forbid even the two *outer* courtyards to carry in the middle
The Beraisa proves Shmuel right on both scores - both with regard to his
opinion in Rebbi Shimon, where the Tana only refers to the members of the
two outer courtyards being permitted to carry in their courtyards, but not
the members of the middle one; and with regard to his opinion in the
Chachamim, where he forbids members of all three courtyards to carry,
unless they made an Eruv combining all three courtyards.
(b) Everyone agrees that when all three courtyards make an Eruv together,
they are combine to become one courtyard, and all three may carry
(c) According to Shmuel, 'Hi Muteres Imahen' - refers, not to the middle
one being permitted to carry in the outer courtyards, but to its being
permitted to carry together with them in the middle courtyard.
(d) When Shmuel said '*Af* Zu Divrei Rebbi Shimon' - he meant that even
Rebbi Shimon, who is more lenient than the Chachamim, agrees with them
here, that one has to be strict.