REVIEW QUESTIONS ON GEMARA AND RASHI
prepared by Rabbi Eliezer Chrysler
Kollel Iyun Hadaf, Jerusalem
Previous dafEruvin 14
ERUVIN 11-15 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) Why does the Mishnah, after saying that a Koreh must be strong enough to
hold an Ari'ach (which is one a half Tefachim wide), go on to give the width
of a Koreh as only *one* Tefach?
(b) The Koreh must be strong enough to hold bricks. What does Rabah bar Rav
Huna say about the posts that support it?
(c) Why may one not carry in a Mavoy whose Koreh is covered with a mat,
which extended downwards, but stopped three Tefachim ground?
(a) What is the Din of a Koreh which extends from one wall but fails to
reach the opposite one, or of two Koros which come out of the two walls, but
which do not meet in the middle?
(b) What does the Tana Kama say about two parallel poles, either of which
cannot support a half-brick?
(c) What does Raban Shimon ben Gamliel hold?
(a) What does Rebbi Yossi b'Rebbi Yehudah hold if the two poles are at
(b) In which case will we not say 'Ro'in'?
(c) Like whom does he hold, and in which point does he disagree with him?
(a) What did Rav say when Rav Yehudah quoted our Mishnah 'Rebbi Yehudah
Omer, Rachbah, Af al Pi she'Einah Beri'ah', to Rav Chiya bar Rav?
Why does the Tana need to add 'Agulah, Ro'in Osah Ke'ilu Hi Meruba'as'? What
is the Chidush *there*?
(b) What is the exception to this?
(c) Having told us Rebbi Yehudah's Din of Ro'in, even though the Koreh is
weak, why did our Tana need to tell us tell us the same thing by a Koreh
made of straw?
(d) Gemara's Kashya 'Peshita?' the Rosh (Si'man 18) deduces that
even the Rabbanan agree with Rebbi Yehudah that 'Akumah, Ro'in Osah Ke'ilu
What is the Chidush? How does the Gemara ultimately answer
the Kashya 'Peshita'?
(a) What do we learn 'Yam shel Shlomoh'?
Answers to questions
(b) What does the Gemara mean when it asks 've'Ha Ika Sefaso'?
(c) In its answer, the Gemara quotes a Pasuk in Melachim which compares the
'Yam' to Perach Shushan. What is 'Perach Shushan? What is the answer?
(d) Why is this answer inadequate?
(a) We learned in a Beraisa that the Yam shel Shlomoh contained a hundred
and fifty Mikva'os.
How much water must there be in a Mikvah for it to be
Kasher, and what figure is that, when transformed into cubic Amos?
(b) The Gemara asks on this Beraisa fact that, if we reckon the Yam
shel Shlomoh as ten by ten by five Amos deep (seeing as its diameter was ten
Amos, and its depth, five), we will have more than a hundred and fifty
Mikva'os. How many cubic Amos would be needed to provide that number of
(c) Why is the Gemara's Kashya a fallacy?
(d) What is the excess of a square over a circle, and how many Mikva'os
should the 'Yam' have provided?
(a) How does the Gemara finally arrive at the correct figure? What was the
shape of the Yam shel Shlomoh?
(b) How do we know that it was not the *top* section that was square, and
the *lower* section, round?
(c) How do we now arrive at the figure of a hundred and fifty Mikva'os?
(a) The Pasuk in Melachim gives the amount of water in the 'Yam' as two
What does that prove?
(b) How do we reconcile this with the Pasuk in Divrei ha'Yamim, which gives
the amount as *three* thousand Bas?
(c) How much must a cupboard or a large container of liquid hold, that it
should no longer be subject to Tum'ah, and why is that? How much is that in
(d) What does the Gemara prove from this Mishnah in Kelim?
(a) What is the minimum height of a Lechi?
(b) A Lechi can be of any width or thickness, according to the Tana Kama.
What does Rebbi Yossi hold?
(c) Our Mishnah speaks of 'Lechayin' in the plural. Does this mean that the
author is Rebbi Eliezer, who requires two Lechayayim for a Mavoy? How does
the Gemara initially explain the plural form of Lechayin?
(d) Then why does the Tana refer to 'Koreh' and not 'Koros' (in the Mishnah
(a) The Gemara describes the Shiur of Kol Shehu of a Lechi as being 'Afilu
What is a 'Chut ha'Sarbol'?
(b) A Lechi that is placed half way along a Mavoy permits one to carry in
the inner half of the Mavoy.
What is the Chidush of this Beraisa?
(c) Will a Lechi that stops between three and four Tefachim short of the
ground be Kasher, according to Raban Shimon ben Gamliel, who holds Levud up
to *four* Tefachim?
(a) Rebbi Yossi requires a Lechi to be three Tefachim wide.
Answers to questions
For which two
reasons did the Gemara feel inclined to rule like Rebbi Yossi in this
(b) Why, in fact, do we *not* rule like him?
(c) According to Rebbi Tarfon, one recites 'Borei Nefashos' over water.
Rebbi Tarfon referring to a Berachah Rishonah or a Berachah Acharonah?
(d) Why do we not rule like him?