ANSWERS TO REVIEW QUESTIONS
prepared by Rabbi Eliezer Chrysler
Kollel Iyun Hadaf, Jerusalem
Previous dafEruvin 33
ERUVIN 31-35 - have been dedicated by Mrs. Rita Grunberger of Queens, N.Y.,
in loving memory of her late husband, Yitzchok Yakov ben Eliyahu Grunberger,
whose Yahrzeit is the 10th of Sivan.
(a) Both an Eruv that is placed on a tree between the heights of three and
ten Tefachim, and one that is placed below three Tefachim is valid; however,
the former may not be taken on Shabbos, whereas the latter may.
(b) The reason for this - is that seeing as within three Tefachim of the
ground is considered joined to the ground (because of 'Levud') Chazal did
not decree on any part of the tree that is less than three Tefachim from the
(c) The Beraisa rules that if an Eruv is placed in a basket which he then
suspends from a tree, even above a height of ten Tefachim - the Eruv is
(a) The Rabbanan say - 'Kol Makom she'Asur Litlo, Ein Eruvo Eruv'.
(b) The Rabbanan cannot be coming to dispute Rebbi's final ruling of the Din
of the basket - because that would mean that the Amora in 'Mi she'Hichshich'
who permits using the side of a tree (e.g. taking something from the basket
that is hanging from the tree and not from tree itself) must be an
individual opinion, and not that of the Rabbanan.
(c) In fact, they are disputing the Reisha of Rebbi, who permits placing an
Eruv on a part of the tree that is lower than ten Tefachim - even though he
is not allowed to take it from there on Shabbos, he may however, take it
during Bein Hashemashos. The Rabbanan maintain that if the Eruv cannot be
taken on Shabbos, then it cannot be taken during Bein Hashemashos either.
Therefore, it is not eligible to be used as an Eruv either.
(a) If the branch is less than four Tefachim square - why should the Eruv be
invalid, even if it is placed above ten Tefachim? An area less than four by
four Tefachim is a Makom Petur, and we have learnt in Shabbos (6a) that one
is permitted to take from it to any other Reshus - so why should he not be
able to take his Eruv from the branch to the Reshus ha'Rabim, where he has
made his residence?
(b) We establish the Reisha of the Beraisa - when the branch is four
Tefachim by on its own, and the Seifa when there is four Tefachim, but only
together with the width of the basket.
(c) Consequently, since the bottom of the tree up to the height of ten
Tefachim, it is not four Tefachim, it is not really a Reshus ha'Yachid, but
still part of the Reshus ha'Rabim, in which case, he and his Eruv are in the
same place. However, without the basket, the Eruv cannot be effective, since
for an Eruv to be effective, it must be put in a place that is Chashuv (at
least four by four Tefachim). In this case, the basket supplements the
Shiur, because Rebbi holds like Rebbi Meir, who holds 'Chokekin Lahashlim'
(i.e. we consider part of the tree - against which the basket is leaning, as
if it would be carved out, now combining with the width of the basket to
make up four Tefachim. Although the top of the tree together with the basket
form a Reshus ha'Yachid of four Tefachim, it is not really a Reshus
ha'Yachid, because it does not reach a width of four Tefachim by the time
it reaches a height of three Tefachim.
(a) 'Na'atz Kanah bi'Reshus ha'Rabim ve'Hini'ach Eruvo Aleha, Gavo'ah Asarah
u'Rechavah Arba'ah, Eruvo Eruv' is not a question of 'Hu be'Makom Echad,
ve'Eruvo be'Makom Acher' - because, someone who acquires his place of
residence in the street is (for the intents and purposes of Eruv) acquiring
a place in a Reshus ha'Yachid, since Chazal give everyone four Amos in all
directions for his Eruv, and 'Reshus ha'Yachid Olah ad la'Raki'a'.
Consequently, both he and his Eruv are, effectively in the Reshus ha'Yachid.
(b) 've'Im La'av, Ein Eruvo Eruv'. Why should his Eruv not be effective when
it is lower than ten Tefachim - since, in any event, both he and his Eruv
are in the same Reshus?
(c) 'Gavo'ah Asarah, Tzarich she'Yehei be'Roshah Arba'ah. Ein Gavo'ah
Asarah, Ein Tzarich' - means that if the board is above ten Tefachim, it
must be at least four Tefachim (because an Eruv requires a Makom Chashuv).
But if it is below ten Tefachim, this is not necessary, since whatever is
below ten Tefachim, is considered as if it was lying on the ground (because
of 'Kelutah ke'Mi she'Hunchah Damya' - See Shabbos, 4a).
(a) Ravina established Rebbi like Rebbi Meir and like Rebbi Yehudah, with
the result that, although we say 'Chokekin Lehashlim', we still need the
tree to be four Tefachim thick within three Tefachim from the ground.
However, that is because we require both the tree and the basket in order to
make up the required four Tefachim for the Eruv. Consequently, if the tree
was not four Tefachim thick near the base, we would need to come on to the
principle of 'Gud Acheis Mechitzasah' in addition to 'Chokekin Lehashlim' -
and we do not combine two principles in this way. It may well be however,
that Ravina agrees with Rebbi Yossi b'Rebbi Yehudah, who gives a four-
Tefachim wide board placed on top of a thin pole in the Reshus ha'Rabim the
Din of a Reshus ha'Yachid, because of Gud Acheis Mechitzasah' alone.
(b) Rebbi Yirmiyah answers the Kashya we asked above on the previous Amud
(that if the tree is four Tefachim wide, why would the fact that it is in a
basket make any difference), by pointing out that, due to the length of the
basket, it is possible to pull the basket down slightly (without removing it
from its current location) and to take the Eruv from it - and we will say
this even if he did not actually pull it down ('Ho'il').
(a) It is possible to make an Eruv without food - by going to the location
of his Eruv and waiting there throughout the duration of Bein Hashemashos.
That point then becomes his residence for that Shabbos.
(b) One needs to put out food - when one cannot go there oneself, and needs
to send a Sheli'ach.
(c) A Sheli'ach who wishes to place an Eruv for two days, i.e. for a Yom-Tov
which falls on Friday, and for the Shabbos that follows - should place it
there before Bein Hashemashos of Yom-Tov, leave it there until night-fall,
and then take it home (in case the Eruv gets lost or eaten by the time
Shabbos arrives. He is then obligated to re-place the Eruv before Bein-
Hashemashos of Shabbos and leave it there until night-fall, when he has the
option to leave it there or to eat it, should he so wish.
(d) If Shabbos precedes Yom-Tov, he will have to leave the Eruv in its
place, and at the termination of Shabbos (before the Bein Hashemashos of
Yom-Tov), he will have to check that the Eruv is still there, before he will
be permitted to use it on Yom-Tov.
(a) When the Gemara asks on Rebbi Yirmiyah, why we do not say 'Ho'il' with
regard to placing an Eruv for two days - it means to ask 'why should it be
necessary to take the Eruv to the chosen location? Why should we not say
'Ho'il' - since he is able to take the Eruv there, it is as if he had taken
(b) In fact, the Gemara could have asked on every case of placing food for
one's Eruv. However, it asked on this Mishnah because it is the only Mishnah
which speaks about carrying the Eruv so explicitly.
(c) The truth of the matter is, replies the Gemara - that we ought to say
Ho'il, like Rebbi Yirmiyah says. However, the Rabbanan decreed not to say it
on any Erev Shabbos and Erev Yom-Tov, because of Yom-Tov that falls after
Shabbos, where it is not possible to take it there on Shabbos, so we cannot
say 'Ho'il', in which case, one has no option but to take the Eruv there