ANSWERS TO REVIEW QUESTIONS
prepared by Rabbi Eliezer Chrysler
Kollel Iyun Hadaf, Jerusalem
Previous dafEruvin 51
ERUVIN 51 - was generously dedicated by an anonymous donor in Los Angeles.
(a) When designating one's new place of residence (by the distant trunk of
the tree) - he must still have time to run to the trunk and arrive there
before nightfall (in effect, before Bein Hashemashos).
(b) When our Mishnah writes 've'Chashchah Lo' - it means that, by the time
he arrived at *his house* (not by the tree-trunk) it had turned dark.
Alternatively, it means that it became dark by the time he *walked* to the
tree-trunk, but had he *run*, he would have reached it beforehand.
(a) Rav Yosef informed Rabah - that he aware of that that tree.
(b) Rabah told Rav Yosef - that he could rely on him, since he *was*, and
Rebbi Yossi, in a Beraisa, permits one traveler (in the same circumstances)
to make the Eruv on behalf of the other.
(c) He quoted Rebbi Yossi, although his name is not mentioned in the
Beraisa, because 'Nimuko Imo', meaning that the Halachah is always like him,
whenever he argues with a contemporary.
(d) 'Nimuko Imo' is the acronym of 'Nim (word) ve'Kav' (straight and
(a) We learn from ...
1. ... "She'vu Ish Tachtav" - that a person who leaves his Techum has four
(b) We prefer to learn "u'Matza Oso Go'el ha'Dam *mi'Chutz* li'Gevul ..."
from the Pasuk "u'Madosem *mi'Chutz* la'Ir, than from that of "mi'Kir ha'Ir
*va'Chutzah"* - since it is preferable to learn "Chutz" from "Chutz" than
"Chutz" from "Chutzah".
2. ... "Al Yetzei Ish mi'Mekomo" - the Techum Shabbos of two thousand Amos
(though this is really an Asmachta, since the Pasuk is referring to
collecting the Man - Mosaf Rashi).
(c) True, it does not matter if the two words of a 'Gezeirah Shavah' are not
exactly the same, it does matter - but that is only if there is not another
potential word which *is*. Then, we will rather learn the 'Gezeirah Shavah'
(a) We learn from "es *Pe'as* Kedmah" - that with regard to Techumin, one
always adds the corners (i.e. to square a circlular town).
(b) The problem with Rebbi Chanina ben Antignos is - that if he *holds* of
the above 'Gezeirah Shavah', then he should also square the circle by Techum
Shabbos, like by the cities of the Kohanim; whereas if he does *not*, then
from where does he know the two thousand Amos of Techum Shabbos?
(c) Really, Rebbi Chanina ben Antignos *does* hold of the 'Gezeirah Shavah'
(with regard to the two thousand Amos). However, the Torah also writes
"*Zeh* Yihyeh Lahem Migreshei he'Arim", which implies 'Zeh' (only here, by
the cities of the Levi'im), does the Din of Pei'os apply, but not by
Note: This entire Sugya appears to learn that Techumin is d'Oraysa - see
(d) The Rabbanan learn from 'Zeh' - 'ka'Zeh Yihyu Kol Shovsei Shabbos',
meaning that the concept of squaring the circle applies to *all* areas of
Shabbos (even when we are speaking about a distance, and not an area), since
that is the diagonal of a square of four Amos). Consequently, four Amos on
Shabbos becomes five and three fifths Amos .
(a) All cases of four Amos with regard to Shabbos - really means five and
three fifths Amos, as we just explained.
(b) Rava asked his disciples whether, if someone throws something from the
street on to a board of four Amos square that is placed on a pole (and for
which he is Chayav) - 'four Amos' should be taken literally, or whether it
means five and three fifths Amos.
(c) Rav Papa and his friends answered - like the second side of the
Sha'aleh, as we learnt above.
(a) According to Rav Nachman, Rebbi Meir and Rebbi Yehudah argue over
whether 'Ikar Eruv be'Pas' (Rebbi Meir) - which explains why he is strict
with regard to a rich man making an Eruv be'Regel; or 'Ikar Eruv be'Regel'
(Rebbi Yehudah) - which explains why he permits it.
(b) Rebbi Yehudah agrees that - even an Eruv be'Regel is only permitted
across the board if one is standing on the spot; making an Eruv in the
distance, is confined to a poor man (who is traveling), but a rich man
cannot do this.
(c) According to Rav Nachman - the author of 've'Zu Hi she'Amru, he'Ani
Me'arev be'Raglav' is Rebbi Meir, and the Chidush is that , although 'Ikar
Eruv be'Pas', Chazal nevertheless permitted a poor man (i.e. a traveler) to
be Me'arev be'Raglav.
(d) And the author of 'Lo Amru Me'arvin be'Pas Ela Lehakel Al he'Ashir
she'Lo Yetzei vi'Ye'arev be'Raglav' - is Rebbi Yehudah (because, according
to Rebbi Meir, that is the Ikar Eruv).
(a) According to Rav Chisda, both Tana'im hold 'Ikar Eruv be'Regel' -
Consequently, Rebbi Meir agrees with Rebbi Yehudah, that even a rich man can
make an Eruv be'Regel - provided he goes to the spot where he wants to be
(b) He disagrees with him however - when it comes to making an Eruv
be'Regel from a distance: Rebbi Yehudah permits this even by a rich man,
whereas Rebbi Meir restricts it to a poor man.
(c) According to Rav Chisda - the Seifa 'Lo Amru Me'arvin be'Pas Ela Lehakel
Al he'Ashir she'Lo Yetzei vi'Ye'arev be'Raglav' - goes according to Rebbi
Meir, as well as Rebbi Yehudah.
(a) Since we rule like Rav Nachman, a rich man is not permitted to make an
Eruv be'Regel from his house; whereas, according to Rebbi Meir, he is not
even permitted to make an Eruv if he walks to the spot where he wishes to be
(b) Rebbi Yehudah brought a proof from the poor men of K'far Shichin and
K'far Chananyah, who made an Eruv on foot to go and fetch dried figs and
raisins in a year of famine, from the residents of Aruma. Now the poor men
of K'far Shichin and K'far Chananyah were living at home, had the Din of
rich men - yet they were permitted to make an Eruv on foot, something which
Rebbi Meir forbade.
(a) From the fact that Rebbi Yehudah permitted only the man who set out to
travel to the neighboring town to complete the journey of four thousand
Amos, and not the other residents of the town (even if they would have made
an Eruv be'Regel) - is a proof for Rav Nachman; because according to Rav
Chisda, even a rich man can also make an Eruv be'Regel on foot.
(b) We are forced to say ...
1. ... that the man set out to go to his house in the second town - because
if he just went to be Koneh Shevisah, he would still be a rich man, in which
case he would be no different than any other of the town's residents.
2. ... that he owned a house in the other town too - because, that is how we
know that he set out to go and reside there (which made him an Ani) and not
just to be Koneh Shevisah at a point somewhere in the middle.
3. ... that he did not say 'Shevisasi be'Makom Peloni' - first of all,
because the Mishnah does not record him as having said so, and secondly,
because if he had, then Rebbi Meir, who agrees that he is an Ani (otherwise,
he should have forbidden him to move at all, and not just restricted him to
'Chamar Gamal'), would have validated the eruv completely.
(a) Every Friday, Rabah bar Rav Chanan would designate a specific spot
between his residence in Artivna and his destination in Pumbedisa as his new
(b) Abaye reminded him that that was the opinion of Rav Chisda, who
maintained that Rebbi Yehudah permits an Ashir to be Me'arev be'Raglav, even
from his house, but that, according to Rav Nachman, this was prohibited. So
(a) Our Mishnah writes that they only permitted to make an Eruv with bread
in order to be lenient with the Ashir - Now if we were to restrict the
concession of 2004 Amos to someone who makes his Eruv on foot, then making
an Eruv with bread would also incorporate the stringency of being confined
to 2000 Amos (instead of 2004); so how can the Mishnah refer to Erav be'Pas
as a leniency?
(b) The answer is - that since the rich man is spared having to walk to his
Techum to wait for night (but is able to send his Sheli'ach), the Mishnah is
justified in calling it a leniency (despite the fact that, in other area, an
Eruv made with bread might result in a stringency).