ANSWERS TO REVIEW QUESTIONS
prepared by Rabbi Eliezer Chrysler
Kollel Iyun Hadaf, Jerusalem
Previous dafEruvin 101
ERUVIN 101 - has been generously dedicated by Rav
Mordechai Rabin of London/Yerushalayim
(a) A Muktzah is a storage-yard behind the house that is not in constant
use, and one tends to make a temporary door which is not properly fitted,
but that can be easily detached and placed on the floor.
(b) To be able to put a door in place, it must be tied and suspended in
thr air (with not even one end touching the ground - which Chazal refer to
(c) Putting up a door which is ...
1. ... not tied - is Binyan.
(d) 'Chadakim she'ba'Pirtzah' - is a bundle of thorns which one uses to
fill in a gap in a wall, and which one sometimes removes.
2. ... tied but not suspended - looks like Binyan.
(a) Rava establishes the Beraisa which permits putting a door in place
even if it is dragging on the ground, by one which *had* a hinge (and is
therefore clearly recognizable as a door) - even if it does not have one
(b) 'Kankan ha'Nigrar' - is the part of the plow-share that one holds on
to - behind the plow, which the Tana in the Beraisa tells, may be used to
bolt a door as long as it is tied even if it is not suspended, but
dragging - as long as it is not lying completely on the ground.
(c) Yom-Tov has exactly the same Din as Shabbos regarding the above.
(a) Deles Almanah is either a door that is made of one piece of wood, or
one whose boards are not connected with bars, which would demonstrate that
it is indeed a door.
(b) The Chidush of 'Deles Almanah ha'Nigreres Ein No'alin Bah' - is that,
even though it has a hinge, it is nevertheless forbidden to put it up.
(a) When placing a Madurta, a Bei'asa, a Kidra, a Puri'a and a Chavita one
must be careful to put the top section in place before the lower one, in
order to avoid Binyan Ohel.
1. Madurta is a fire, where one places some logs on top of others that are
placed slightly apart (thereby forming an Ohel - which is the central
issue in all the cases).
2. Bei'asa is eggs that one places on top of two pieces of wood placed
slightly apart, over the fire to roast.
(c) The first three cases are speaking about Yom-Tov, not Shabbos.
3. Is a pot that one places on top of two barrels placed slightly apart.
4. Puri'ah is a portable leather bed that one fits on to a frame by means
4. Chavita is the way that one arranges the barrels, one on top of the
other, in the wine-cellar.
(d) Rebbi Yehoshua explained the analogy of the Tzadikim to thorns by
establishing the thorns as the bundle of thorns referred to above (in 1d):
Just as the bundle of thorns protect the breach, so too, do the Tzadikim
shield over Klal Yisrael. Alternatively, the Navi means to say that the
Tzadikim cause the evil nations of the world to become crushed in the
World to Come.
(a) Rebbi Meir prohibits standing in a Reshus ha'Yachid and opening a door
in a Reshus ha'Rabim or vice-versa - because he is afraid that one may
transfer the key to where he is standing.
(b) The case of standing in a Reshus ha'Rabim and opening a door in a
Reshus ha'Yachid speaks when he takes the key from the roof to open the
door in a lock which is higher than ten Tefachim; Rebbi Meir is afraid
that he will lower the key to within ten Tefachim from the ground.
(c) In order to be allowed to carry, he will be obligated to build himself
a Mechitzah of ten Tefachim on three sides, thereby enclosing the entire
space in question, and forming a Reshus haYachid.
(d) But how can that be, the Chachamim asked Rebbi Meir? That is exactly
what happened in the butcher's market, and they all used to open the door
using the key placed on the window-ledge near the door (which was *above*
ten Tefachim, as was the lock)?
(a) Yerushalayim is a Karmelis because the doors at both ends of its main
road were kept locked at night.
(b) Rav Papa answers this by differentiating between the time *before* the
walls of Yerushalayim (and its doors) were breached (when it is a
Karmelis), and *afterwards* (when it became a Reshus ha'Rabim - and that
is when our Mishnah speaks).
(c) A garden is considered a Karmelis - because it is more than a Beis
Sasayim, and not Hukaf le'Dirah.
(d) Rebbi Meir is speaking about taking the key for the garden through a
hole in the wall which divides between his yard and the garden, and wants
to open the door via the garden.
7) Regarding a garden which adjoins a Reshus ha'Rabim, when there is a
Beis Sha'ar adjoining the door that leads from one to the other, Rebbi
Meir holds that he can only open the door from inside the Beis Sha'ar, on
whichever side it is.
(a) To open the lock of a shop that is below ten Tefachim from the street
-one must place the key on the floor of the threshold.
(b) When the Tana says '*ve'Chen* Chanuyos ha'Pesuchos li'Reshus ha'Rabim,
bi'Zeman she'ha'Man'ul le'Matah me'Asarah Tefachim' - he wants to inform
us that he is speaking about an Iskupas Karmelis, otherwise, Rebbi Meir
would not permit standing in one major Reshus and carrying in another - as
we saw in the Reisha (of 'Pischei Sha'arei Ginah' - see Tosfos DH
(c) From the fact that Rebbi Meir now permits standing in the street and
moving the key (below ten Tefachim) in a Karmelis, we learn that Rebbi
Meir retracted from his original stance, in forbidding even *that* (as we
saw a little earlier).
(a) If the lock is above ten Tefachim, he leaves the key on top of the
lock, or on a window-ledge that is higher than ten Tefachim, from which he
is permitted to take it when he stands on the Iskupah.
(b) If the surface-area of the lock would be ...
1. ...less than four by four Tefachim - then it would be a Makom Petur.
Why would Rebbi Meir forbid taking from it even if it was *above* ten
Tefachim and the actual lock was *lower*.
(c) We therefore establish the surface-area of the lock as being less than
four by four Tefachim, but with additional space from which one could cut
out to make it four by four: Rebbi Meir holds 'Chokekin Lehashlim (as we
learnt above on Daf 11a) - making the area in question a Reshus haYachid,
and the Rabbanan do not (in which case it remains a Makpm Petur).
2. ... more than four by four Tefachim - then how can the Rabbanan permit
taking the key from the Iskupas Karmelis to open a door in the Reshus
ha'Yachid (above ten Tefachim)?
(d) We also learn from the Rabbanan (who forbid taking from the Iskupas
Karmelis and after opening the lock [a Makom Petur], to place the key on
the window-ledge which is above ten Tefachim and more than four by four
Tefachim) that one may not use a Makom Petur to transfer from one Reshus
to another (even if one of them is Reshus de'Rabbanan - like Ze'iri on
(a) Bolting a door using a straight bolt that is not fixed to the door,
is prohibited - because the (unformed) bolt is Muktzah.
(b) Rebbi Yossi permits a 'Nagar she'Yesh be'Rosho Gelustera' i.e. a bolt
that has a thickened top and is fit to use as a pestle to pound pepper, in
which case it is a K'li (albeit a K'li she'Melachto le'Isur), and may now
be used as a bolt.
(c) Rebbi Yossi argues that (by the incident with Raban Gamliel and the
Elders) it was exactly the opposite: initially, it was customarily
forbidden, and it was the Elders who permitted it.
(d) The Machlokes Tana'im is when the rounded bolt is tied, but with such
weak string, that if one were to attempt to pick it up by the string, the
string would break. Rebbi Yossi considers this sufficient to render it
tied, Rebbi Eliezer does not - and we are now about to learn that a bolt
must be fixed or at least tied to the door before it may be used.