ANSWERS TO REVIEW QUESTIONS
prepared by Rabbi Eliezer Chrysler
Kollel Iyun Hadaf, Jerusalem
Previous dafEruvin 38
ERUVIN 38 & 39 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) Rebbi Eliezer permits a person to place two Eruvin, one to the east
and one to the west, the one to be effective on the Yom-Tov, the other, on
the Shabbos that follows it (or vice-versa) - because he holds that
Shabbos and Yom-Tov are two separate sanctities.
(b) The Rabbanan hold that Shabbos and Yom-Tov are the same sanctity.
Consequently, one cannot change one's direction from one day to the next -
any more than one can in the middle of the day.
(c) No! There is no difference between this case and one in which he
places one Eruv and makes a condition to use it on one day, and to retain
his regular home as his residence on the other - in either case, Rebbi
Eliezer will permit changing from Shabbos to Yom-Tov (or vice-versa), and
the Rabbanan will forbid it.
(a) The Rabbanan agree that if the Eruv was eaten in the course of the
first day, it is not valid on the second - which would obviously not be
the case if the two days shared one sanctity. That is why Rebbi Eliezer
asked the Rabbanan in surprise 'But you agree with me that they have two
(b) The Rabbanan first asked Rebbi Eliezer whether he does not agree with
them that one cannot make an Eruv for half a day to the north, and for the
second half to the south, even in the same direction (that is what they
mean by 'in one direction' - i.e. either one places the Eruv in one
direction, or not at all)? When he answered in the affirmative, they
argued that, in that case, neither can one make an Eruv one day in the
east and the next, in the west (which is what they mean by 'two days').
(c) Rebbi Eliezer answers this by saying that, whereas one day comprises
only *one* sanctity (and cannot therefore be divided into two), two days
comprise *two* sanctities, and there is therefore is no reason why one
should not be able to divide them into two directions.
(d) Rebbi Eliezer's second proof is need to make a new Eruv that
one needs to make on foot on the second day (and that one cannot rely on
the Eruv that he made on the first day, when he went there before the
beginning of Beis Hashemashos) Here too, the Rabbanan conceded this. Does
this not prove, he asked them, that even *they* agreed that Shabbos and
Yom-Tov have two different sanctities?
(a) In fact, the Rabbanan were uncertain whether the two days have one
sanctity, or two. Consequently, they adopted both opinions Lechumra (which
explains why they agreed with both proofs of Rebbi Eliezer, since both
(b) They go Lechumra both as regards forbidding setting up an Eruv in two
directions on the two days (because maybe they comprise *one* sanctity),
and they also go Lechumra to invalidate the Eruv on the second day, if it
was eaten on the first (because maybe they comprise *two*).
(c) According to Rebbi Eliezer, one is not permitted to place an Eruv on
Yom-Tov for Shabbos - because of 'Hachanah' (the prohibition of preparing
on Yom-Tov for Shabbos or vice-versa, as will be explained on the next
(a) According to Rebbi, someone who made an Eruv by waiting on the spot of
his chosen residence during the first Bein Hashemashos until Shabbos
entered , must nevertheless repeat this on the second day. And if his Eruv
was eaten on the first day - he may not rely on it to go beyond that
point on the second day - The reason for both of these rulings is because
Rebbi holds that Shabbos and Yom-Tov, comprise two sanctities (like Rebbi
(b) Rebbi Yehudah holds 'Harei Zeh Chamar Gamal - because he holds like
the Rabbanan of Rebbi Eliezer, who are uncertain whether they comprise two
sanctities or one. Consequently, he goes Lechumra both ways.
(c) In fact, the Gemara concludes, Raban Shimon ben Gamliel and Rebbi
Yishmael the son of Rebbi Yishmael ben Berokah - hold that the two days
have two sanctities, like Rebbi, and the Beraisa must be amended to read
(after the words of Rebbi) 'and that is also the opinion of Raban Shimon
ben Gamliel and Rebbi Yishmael the son of Rebbi Yishmael ben Berokah'.
(a) We rule like Rebbi (and those who follow his opinion), but the author
of this opinion is really Rebbi Eliezer.
(b) The reason that, when Rav issued his ruling, he does not also quote
Rebbi by name - is because in reality, Rebbi himself only quoted the
opinion, without agreeing with it.
(c) Rav had a tradition that Raban Shimon ben Gamliel and Rebbi Yishmael
the son of Rebbi Yishmael ben Berokah actually hold that Shabbos and Yom-
Tov comprise two sanctities, and were not just quoting it like Rebbi did.
(d) The Gemara refers to Rebbi Yossi b'Rebbi Yehudah as S'timta'ah -
because on many occasions, Rebbi concurred with his opinion, and went on
to insert it in the Mishnah, in the form of a S'tam Mishnah.
(a) Rabah explains that, although Rav ruled above like Rebbi Eliezer, he
nevertheless forbids an egg that was laid on Shabbos, to be eaten Yom-Tov
or vice-versa - because of Hachanah, which is forbidden, because the Torah
writes in Beshalach "ve'Hechinu es Asher Yavi'u", from which Chazal derive
that Shabbos and Yom-Tov must be prepared on a week-day, and not Shabbos
on Yom-Tov or vice-versa.
(b) Nevertheless, one may re-place the Eruv on Yom-Tov, to permit going
there on Shabbos - because he holds that it is the beginning of the day
that acquires the Eruv (i.e. advent of Shabbos), and not the end of Erev
Shabbos. Consequently, it is a matter of Shabbos preparing for itself, and
not Yom-Tov for Shabbos.
(c) The reason that if he placed the jar of Ma'aser wine (which he has
declared Terumas Ma'aser when Shabbos enters) for an Eruv, it is not
valid, is because the Eruv must be edible when it is placed, which in this
case it is not.
(d) The case when someone places two Eruvin for the two consecutive days,
one in the east and one in the west, and which Rebbi Eliezer permits (each
Eruv on its respective day) - speaks when the two Eruvin were placed not
at the end of the two thousand Amah extremity (in which case the Eruv in
the West will not be accessible east on the first day, but only
at a distance of one thousand Amah on either side, enabling him to go
three thousand Amos in each direction, as the Eruv falls due - but which
also allow him to go from one Eruv to the other when the first Eruv falls
(a) The Gemara initially thinks - that when one makes an Eruv 'on foot'
(without food) one is obligated to actually state this verbally for the
Eruv to be effective, and, since it is not possible to know exactly when
Shabbos comes in, one has no option but to make the statement whilst it is
still day (even though we established that, according to Rebbi Eliezer,
the beginning of the day acquires the Eruv). So the question arises, how
can Rebbi Eliezer permit preparing an Eruv on foot on the first day for
(b) In fact however, Rebbi Eliezer has no problem with this - because the
truth of the matter is that it is not necessary to say anything, only to
sit at the chosen spot and wait for Shabbos to enter, something that is
not called 'Hachanah'.
(c) The Gemara at first thought that Rebbi Eliezer holds like Rebbi
Yochanan ben Nuri, who says; with regard to someone who falls asleep
whilst waiting at his chosen spot for Shabbos to come in, is nevertheless
'Koneh Shevisah', like property of Hefker, which acquire Shevisah
automatically - 'Cheftzei Hefker Konin Shevisah'.
(d) It is possible, the Gemara concludes, that Rebbi Eliezer will even
hold like the Rabbanan, who hold that a sleeping person cannot acquire an
Eruv - because that is only when he is asleep and is unable to talk; but
if he is awake, and is able to talk, even the Rabbanan could agree with
Rebbi Eliezer, that since he is *able* to state that he is Koneh
Shevisah, he does not actually need to do so (like the principle of 'Kol
ha'Ra'uy le'Bilah, Ein Bilah Me'akeves Bo').
(a) The Beraisa forbids someone to walk around his field on Shabbos to see
what needs repairing - because of the Pasuk in Yeshayah "mi'Metzo
(b) The Beraisa also forbids someone to go to the gates of the city - in
order to be ready, the moment it turns night, to leave the city and go to
(c) Nevertheless, Rabah, in the name of the Beraisa, permits going as far
as the Techum in order to make an Eruv - because it is not evident that
he is doing anything untoward, since if he is a Talmid-Chacham, people
will say that he is walking around because he is learning. Whereas in the
two cases in the Beraisa, since it is obvious why he is walking around his
field or waiting by the border, it is forbidden because of Mar'is ha'Ayin.