ANSWERS TO REVIEW QUESTIONS
prepared by Rabbi Eliezer Chrysler
Kollel Iyun Hadaf, Jerusalem
Previous dafEruvin 45
ERUVIN 45 - Dedicated in memory of Meir Menachem (Max)
Turkel, whose Yahrzeit is the 5th of Teves, by his wife, Jean, and his
sons, Eddie and Lawrence Turkel.
(a) The Seifa of our Mishnah does not allow someone who left his Techum
legally e.g. to save from the enemy or from an overflowing river, to
return (under the circumstances mentioned there) even if it is *more* than
two thousand Amos, like we thought at first. - What the Mishnah is coming
to permit is soldiers who left the Techum with their weapons, in order to
save Jews from enemies who were attacking them, to return even with their
weapons (to tell us that they are not obligated to leave their weapons by
the first house that they found).
According to Rav Nachman bar Yitzchak, the Mishnah in Rosh Hashanah, which
limits the soldiers to two thousand Amos, is speaking when they were the
victors, whereas our Mishnah, which permits even more, speaks when they
were the vanquished, in which case they need to escape, like we learnt
(b) We could answer the contradiction between the Reisha of the Mishnah
(which limits someone who returns to *two thousand Amos* from where he is
when he discovers that his journey is no longer necessary) and the Seifa
(which permits him to walk *any distance* to return to his Techum), by
explaining that the latter is permitted because it speaks about someone
who went to save from the enemy. *He* is permitted to return whatever the
distance to save his life, because the enemy might give chase - which is
not the case in the Reisha, which speaks about the other categories of
people who leave the Techum legally, and whose lives are not in danger.
(c) The Mishnah in Rosh Hashanah permits anyone who left his Techum,
(including someone who did so in order to save from a band of robbers) to
walk two thousand Amos, and no more - that certainly clashes with the
Seifa of our Mishnah, which appears to permit even more than two thousand
Amos. Therefore, the Gemara needs to establish the Seifa of our Mishnah
not with regard to the concession of walking more than two thousand Amos,
but with regard to returning with their weapons.
(d) It happened once - that the returning soldiers left their weapons in
the first house that they arrived at. The enemy noticed this however, and
attacked. In the ensuing rush to retrieve their weapons, more soldiers
killed each other, than were killed by the enemy. That was when Chazal
issued the concession to return all the way home with their weapons.
(a) It is always permitted to attack a besieging army and to transgress
Shabbos - when it is a border town that is being besieged.
(b) If the town that is under siege is not a border town, then one may
attack the enemy and break the Shabbos - provided the enemy have come to
kill, but not if what they only want money or property.
(c) Neherda'a in Bavel is considered a border town (See Toras Chayim).
(a) Ke'ilah was a border town - which explains why David ha'Melech
attacked them on Shabbos.
(b) If David ha'Melech wished to know whether or not he was permitted to
attack Ke'ilah on Shabbos - then he should have consulted, not the Urim
ve'Tumim, but the Beis-Din of Shmuel ha'Ramasi (due to the principle of
'Lo ba'Shamayim Hi')?
(c) What he consulted the Urim ve'Tumim about - was whether he would be
successful in his attack. The proof for this is from the Urim ve'Tumim's
reply 'Go and strike the Pelishtim *and you will save Ke'ilah*'.
(a) According to Rebbi Meir, someone who stopped at a certain spot just
before Shabbos, and who was unaware that he was actually within the Techum
of a town - is not permitted to enter the town i.e. to walk the entire
town like the residents of the town are permitted to do. He is however,
permitted to walk two thousand Amos from his current location in any
direction - even into the town.
(b) Rebbi Yehudah testified that this happened once to Rebbi Tarfon - who
subsequently entered the town and, and went straight to the Beis
ha'Medrash, where he Darshened all day.
(c) Perhaps, suggested Rebbi Akiva - Rebbi Tarfon *did* know that he was
within the Techum of the town (and Rebbi Yehudah erred in believing that
he did not). In addition, who says that the Beis-ha'Medrash was not within
his two thousand Amos?
(a) According to the Chachamim, if a traveler was asleep when Shabbos came
in - he only has four Amos when he wakes up.
(b) Rebbi Eliezer allows him only two Amos in each direction.
(c) Rebbi Yehudah maintains that he is allowed four Amos in any one
direction that he chooses, but not in any other.
(d) The Tana is strict here, by someone who is Koneh Shevisah (either with
food or on foot), forbidding him to take from outside his four Amos to
inside (and the same applies to someone who leaves his Techum) - because
the four Amos that he has is like a Reshus ha'Yachid, and carrying
anything from another Reshus to a Reshus ha'Yachid is prohibited. Whereas
in the case when someone's Techum ends in the middle of the town, where
both inside his Techum and outside it are one and the same Reshus he will
be premitted to throw outside his Techum (and similarly if his Techum
outside the town is a Reshus ha'Rabim, where, both inside his Techum and
outside it, are one and the same Reshus, he will be allowed to move
something less than four Amos from outside his Techum to inside or vice-
(a) The Tana Kama writes about three travelers, when two Amos of the
middle one overlap two Amos of one of the outer ones on the one side, and
two Amos of the other one on the other side, but when the four Amos of
each of the outer ones do not overlap at all - then the middle one is
permitted to carry in the areas of the two outer ones, and vice-versa; but
the two outer ones are forbidden to carry in each other's area.
(b) Concerning the three courtyards which are situated side by side, each
of which opens independently into the street: when the outer two made an
Eruv with the one in the middle - if the courtyards opened into each
other, it would be forbidden to carry in *any* of the courtyards, since
the inside courtyard would forbid carrying in the others (as will be
(a) If Rebbi Yochanan's reason is because no Da'as is needed to acquire
Shevisah, and even objects that are Hefker will acquire Shevisah, then he
and the Rabbanan argue by people (rather than by vessels) that are Hefker
- to teach us how far the Rabbanan go, that even by people, where we could
say that, since when he is awake, he is Koneh Shevisah, he will also be
Koneh Shevisah when he is asleep. Yet they do not say that; even there,
they rule he is not Koneh Shevisah.
(b) If Rebbi Yochanan ben Nuri holds that objects that are Hefker do *not*
acquire Shevisah, then his reason (for holding that a sleeping person is
Koneh Shevisah) - is because: since when he is awake, he is Koneh
Shevisah, he will also be Koneh Shevisah when he is asleep.
(c) The Beraisa rules that rainwater which fell on Erev Yom-Tov is Koneh
Shevisah, and may be carried two thousand Amos in all directions. Now the
author of this Beraisa can only be Rebbi Yochanan ben Nuri - and the rain-
water can only be Koneh Shevisah because of Cheftzei Hefker Konin
(d) Rav Safra tries to refute this proof - on the grounds that the rain-
water acquires Shevisah, not for the above reason, but because it speaks
when it had collected near the town, and it is Koneh Shevisah like the
residents of the town, who had their minds on it from before Yom-Tov.
(a) We establish the Beraisa, which gives wells of the Olei Regalim two
thousand Amos - like Rebbi Yochanan ben Nuri, who holds that 'Cheftzei
Hefker Konin Shevisah'; and the Mishnah, which holds 'ke'Raglei
ha'Memalei' - like the Rabbanan.
(b) This proves that Rebbi Yochanan ben Nuri holds that 'Cheftzei Hefker
Konin Shevisah' - like we learnt at first, and not like Rav Safra, who
tried to refute that.
(c) Why did you not refute Rav Safra's contention from the Lashon of the
Beraisa under discussion, Rav Yosef asked Abaye? - The Beraisa says 'Yesh
Lahen Alpayim Amah le'Chol Ru'ach', when, according to Rav Safra, it
should have said 'ke'Raglei Anshei Osah ha'Ir'?
(a) It is Rebbi Eliezer who maintains that the rain comes from the water
of the oceans. According to him, why should the rain-water not acquire
Shevisah in its place in the ocean when Yom-Tov enters? Consequently, it
would appear, contends the Gemara, that the Beraisa, which rules that rain
which fell on Yom-Tov acquires Shevisah like the person who eventually
draws it, and not in the ocean, must go like Rebbi Yehoshua, who holds
that the rain comes from the sky.
(b) According to the current contention in Rebbi Eliezer, one will only be
permitted to carry the rain-water which fell on Yom-Tov - four Amos
(because it left its Techum on Yom-Tov).
(c) We establish the Beraisa even like Rebbi Eliezer, by further
establishing it when the rain came from clouds that we recognize in the
sky from the previous day. Alternatively, we simply assume these clouds to
be the ones from the previous day - because it is only a Safek
de'Rabbanan, and we will be lenient when there is a doubt.
(a) If there was Techumin above ten Tefachim, argues the Gemara - then why
would the rain not be Koneh Shevisah in the clouds?
(b) The contention that the water cannot acquire Shevisah in the clouds
because it is totally absorbed in the clouds, and is therefore considered
non-existent, is not acceptable - because if we say that, then the rain
which eventually falls should be Muktzah because it is 'Nolad', in which
case, nobody would be permitted to frink it?
(c) The reason that the water did not acquire Shevisah in the clouds - is
because it is constantly moving, and a moving object is not Koneh
(d) In that case, the Gemara concludes, we can also establish the Beraisa
which gives rain-water the Techum of whoever collects it (and not from its
place in the ocean) - like Rebbi Yochanan ben Nuri, who holds 'Cheftzei
Hefker Konin Shevisah'. Rainwater that comes from the sea however, is
different, because it is constantly moving.