ANSWERS TO REVIEW QUESTIONS
prepared by Rabbi Eliezer Chrysler
Kollel Iyun Hadaf, Jerusalem
Previous dafEruvin 34
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) If someone who wants his place of residence (over Shabbos) to be in the
street, and he then places his Eruv on a wall in the street which is within
ten Tefachim - we have already learned that everyone has four Amos from the
place where he is standing, which is called (with regard to the Din of Eruv)
a Reshus ha'Yachid. That being the case, his Eruv would be effective whether
he placed the Eruv above ten Tefachim or below it. Consequently, we are
forced to establish the Beraisa which differentiates between an Eruv that is
above ten Tefachim and one which is below that, by a wall which is more than
four Amos away.
(b) If he placed his Eruv below ten Tefachim it is effective - due to the
fact that both he and his Eruv are in the same Reshus (ha'Rabim), and
because, during Bein Hashemashos, he is able to bring the Eruv to his
'residence' by carrying it less than four Amos at a time. When the Eruv is
placed above ten Tefachim however, his Eruv is not valid, since he is in a
Reshus ha'Rabim and his Eruv, in a Reshus ha'Yachid. Nor is there any Heter
to carry from one Reshus to the other, even during Bein Hashemashos.
(a) If he intends his place of residence to be a dove-cot (with different
levels) or in a large cupboard above ten Tefachim, and he places his Eruv
above ten Tefachim (though not in his actual place of residence), the Eruv
is effective, despite the fact that he is forbidden to take the Eruv from
the one shelf in the cupboard to the other (via the air above the Reshus
ha'Rabim) - because he is able to move down to where the Eruv is, and eat it
there (which is nevertheless called 'Hu ve'Eruvo be'Makom Echad', since they
are both in the Reshus ha'Rabim). However, if the Eruv is placed below ten
Tefachim, it remains forbidden to take the Eruv to him (since it constitutes
carrying from a Karmelis to a Reshus ha'Yachid via the air of a Reshus
ha'Rabim). Nor will the fact that he is able to move down to the Eruv and
eat it there, because, since he acquired his residence in a Reshus
ha'Yachid, and he now wants to eat his Eruv in a Karmelis, that is still
called 'Hu be'Makom Echad ve'Eruvo be'Makom Acher'.
(b) It is forbidden to move the Eruv from its location to his place of
residence, even when both are above ten Tefachim - because it is forbidden
to carry from a Reshus ha'Yachid to a Reshus ha'Yachid via the air of a
Reshus ha'Rabim - even above ten Tefachim (where the air itself is a Reshus
(c) According to Rebbi Yirmiyah, asks the Gemara, the Eruv should be valid,
even if it was placed below ten Tefachim, because of 'Ho'il' - meaning that
one could have knocked the cupboard to the ground, in which case his place
of residence would change to below ten Tefachim, and he would then be taking
from a Karmelis to a Karmelis via a Reshus ha'Rabim, which is only
de'Rabbanan, and this Tana holds like Rebbi (that Chazal did not decree on a
Shevus, during Bein Hashemashos). Note: It is not clear however, how this
differs from the actual case in question (i.e. even without Ho'il), since
carrying from a Karmelis to a Reshus ha'Yachid via the Reshus ha'Rabim is
also no more than an Isur de'Rabbanan (see Tosfos DH 'O').
(a) We are speaking here, answers the Gemara, about ...
1. ... a cupboard that is attached to the wall with nails, and cannot be
moved from the wall, in which case, 'Ho'il' will not be applicable?
(b) If the Eruv was attached to a string, which one could pull up from the
one shelf to the other via a skylight in the cupboard - the Eruv would be
valid even if it was below ten Tefachim, because then he would be pulling
the Eruv from a Karmelis to a Reshus ha'Yachid directly, which involves no
aspect of d'Oraysa at all.
2. ... a long cupboard that is more than four Amos tall. Consequently, even
if we knock it over, the new place of residence (where the top of the
cupboard is now lying) will be at least four Amos away from where the Eruv
is placed, in which case 'Hu be'Makom Echad ve'Eruvo be'Makom Acher' will
apply, despite the fact that both locations are in the same Reshus.
(a) If the pit is situated in a Reshus ha'Rabim - then it will depend upon
where he intends to acquire his residence. If he intends it to be outside
the pit, then his Eruv will not be valid, because he is in one Reshus, and
his Eruv is in another (so why does our Mishnah validate it). Whereas if he
intends to acquire his residence inside the pit, then it is obvious that his
Eruv will be valid (in which case, the Mishnah is redundant).
(b) Our Mishnah must therefore be speaking - when the pit is in a Karmelis,
and where he intends to acquire his residence outside the pit. The Chidush
of our Mishnah - is that, even though taking the Eruv from the Reshus
ha'Yachid to a Karmelis constitutes an Isur de'Rabbanan, the Eruv is
nevertheless valid, because the Tana of our Mishnah holds like Rebbi, who
maintains that Chazal did not decree Shevusin during the period of Bein
Hashemashos, which is when the Eruv becomes operational.
(a) Since the Tana invalidates an Eruv on top of a reed or a stake if it is
attached (although this involves nothing more than an Isur de'Rabbanan) he
must hold like the Rabbanan of Rebbi - who decree Shevusin even during the
Bein Hashemashos period. Consequently, it will be forbidden to remove the
Eruv even during Bein Hashemashos, which will render the Eruv invalid.
(b) According to Ravina, the author of this Mishnah could even be Rebbi -
who will agree by a reed or a stake, compared to a tree, are soft, and there
is a strong suspicion that one may come to break a twig (see Ritva).
(a) When the town hosted numerous troops, and there was no room for the
Talmidim in the Beis-Hamedrash - Rav Nachman advised them to go down to the
fields and bend reeds to form stools to sit on.
(b) Rav Nachman was speaking about *soft* reeds (on which Chazal did not
issue any decree), whereas our Mishnah is speaking about a reed that has
hardened, and now resembles a tree (though it is somewhat softer than it).
(c) One Beraisa considers reeds and bushes as trees, which are *not*
Kil'ayim in a vineyard, whereas another Beraisa considers them vegetables,
which *are*. Clearly, the first Beraisa is referring to hardened reeds, and
the second, to soft ones.
(d) The Mishnah which writes 'Ein Markivin Pigam al Gabei Kidah Levanah' -
categorizes 'Kidah Levanah' as a tree; Whereas plain Kidan is a vegetable,
and which therefore constitutes Kil'ayim when planted in a vineyard.
(a) The Gemara initially considers an Eruv placed in a cupboard whose key is
lost, to be 'Hu be'Makom Echad, ve'Eruvo be'Makom Acher' - because his Eruv
(b) The Gemara establishes our Mishnah by a cupboard made of un-cemented
bricks - Such a cupboard is easy to take apart, and, according to Rebbi
Meir, taking it apart is even permitted. Consequently, the Eruv *is*
(c) The Tana Kama of Rebbi Meir, who permits taking from the hole, if some
of the bricks caved in, but not to actually remove any bricks - is Rebbi
Shimon, who does not hold of Muktzah.
(d) Our Mishnah pertains to Yom-Tov, not to Shabbos - since Shmuel is quoted
as saying that Rebbi Meir's Din is confined to Yom-Tov and does not extend
(a) Rebbi Eliezer says that if the key of a tower made of loose bricks got
lost, the Eruv is invalid.
(b) The third Tana holds that, if the key was lost in town, the Eruv is
valid (because he holds like Rebbi Shimon, who maintains that the roofs and
the enclosures of the town are all considered one - and that one may carry
from one to the other). Consequently, if the key is found, he will be able
to carry it to the cupboard and open it; whereas if it was lost in the
fields, then even if it is found, he will have to leave it where it is.
Consequently, he will be unable to open the cupboard, and the Eruv will be
invalid. This Tana however, is speaking about Shabbos, not about Yom-Tov,
when it is permitted either way, though not for Rebbi Meir's reason, but
because we contend with the key being found. Note: We are assuming that when
he lost the key in town, he lost it in the vicinity of his home, and not in
(c) It is conceivable, explains Rashi (in his second explanation, that Rebbi
Eliezer in our Mishnah, who invalidates the Eruv, is speaking about when the
key was lost *in the field*, and he can still be the author of the Beraisa,
which permits the Eruv when the key was lost *in town*. (See however, Tosfos
35a DH 'Chasurei').
(d) The Tana Kama of this Beraisa holds like Rebbi Meir in our Mishnah, who
validates the Eruv, irrespective of where the key was lost.