THOUGHTS ON THE DAILY DAF
brought to you by Kollel Iyun Hadaf of Har Nof
Rosh Kollel: Rav Mordecai Kornfeld
Ask A Question about the Daf
1) DERIVING A HALACHAH FROM A "MEH HA'TZAD"
QUESTION: The Gemara says that Rebbi Eliezer needs a separate verse to
teach that the *preparations* for each of various Mitzvos are permitted to
be done on Shabbos, even though they involve doing Melachah. The Gemara
explains why *one* verse does not suffice to serve as the source for doing
the preparations for all Mitzvos on Shabbos.
2) LEARNING A LAW FROM SUKAH FOR LULAV
However, normally, when there are two verses that teach that a certain
Halachah applies to two different items, we can learn that it applies to
all other items through the use of a "Mah ha'Tzad." Why, then, does the
Gemara not suggest that we can learn Rebbi Eliezer's Halachah that the
preparations of a Mitzvah override Shabbos from *two* verses, through a
(a) TOSFOS (DH Iy m'Omer), citing Rav Poras, answers that the Gemara must
have known that there was some question (Pircha) that prevented the
Halachah from being derived through a "Mah ha'Tzad." That is, had the
Gemara suggested a Mah ha'Tzad, it would have countered that each of the
cases mentioned has something which makes it unique from all the other
cases, such that it cannot be learned from a Mah ha'Tzad.
(b) Tosfos suggests a second answer: Indeed the Gemara could have derived
this Halachah from a "Mah ha'Tzad." Nevertheless, there it is feasible that
a verse was written in the Torah to teach explicitly a Halachah that
otherwise could have been deduced through a "Mah ha'Tzad," in order to make
it more clear. (This is known as "Tarach v'Kasav La Kra"; the Gemara
actually only applies this principle to what is learned from a Kal
v'Chomer, see Pesachim 18b etc.) Therefore, the Gemara does not feel it
necessary to show that the Halachos in question could not have been learned
from a Mah ha'Tzad.
However, if the Halachah could have been derived from *one* verse through a
"Binyan Av," there would have been no need for the verse to mention it
explicitly. A "Binyan Av" is just as clear as an explicit teaching.
QUESTION: The Gemara says that according to Rebbi Eliezer, the Halachah
that preparations for the Mitzvah of Lulav override Shabbos is derived from
the word "ba'Yom" which appears in a verse discussing Lulav. The Rabanan,
though, maintain that that phrase is needed to teach that the Mitzvah of
Lulav is performed only during the day and not at night, because we might
have compared Lulav to Sukah through a Gezeirah Shavah between the two
(from the words "Shiv'as Yamim") and assumed that just like the Mitzvah of
Sukah applies at night, so, too, does the Mitzvah of Lulav.
Rebbi Eliezer, though, does not need a second phrase to teach that the
Mitzvah of Lulav is not performed at night. It seems that Rebbi Eliezer
maintained that there was no reason to compare Sukah to Lulav; he argued
that there is no Gezeirah Shavah of "Shiv'as Yamim." However, in the
following lines of the Gemara, Rebbi Eliezer says that the reason why the
preparations for the Mitzvah of Sukah override Shabbos is because of the
Gezeirah Shavah comparing Sukah to Lulav!
If Rebbi Eliezer accepts the Gezeirah Shavah between Lulav and Sukah, then
why does he not require another verse to teach that the Mitzvah of Lulav is
performed only during the day (and not at night as well, like Sukah)?
(a) TOSFOS (DH Shiv'as) answers that although Rebbi Eliezer agrees that
there is a Gezeirah Shavah, he maintains that it cannot be applied when the
very words used for the Gezeirah Shavah -- "Shiv'as Yamim" ("seven days")
-- seem to preclude the law derived from it! That is, the word "days"
cannot teach that just like the Mitzvah of Sukah is performed at night, so,
too, the Mitzvah of Lulav is performed at *night*, because such a teaching
would contradict the simple meaning of the words used for the Gezeirah
Shavah -- "seven *days*."
(b) The RE'AH and RITVA answer that Rebbi Eliezer maintained that the Sukah
and Lulav cannot be compared as far as night is concerned for another
reason. With regard to Sukah, the Halachah is that the Mitzvah applies
*all* day and *all* night. This Halachah cannot be applied to Lulav,
because the Torah certainly does not require that the Lulav be held all day
and all night. On the other hand, it is unacceptable to suggest that the
Gezeirah Shavah teaches that one must pick up the Lulav *once* at night,
because then the Halachah with regard to Lulav is not similar to the
Halachah with regard to Sukah, from which the Halachah is derived.
(c) The RASHBA explains that Rebbi Eliezer indeed learns from a verse that
the Mitzvah of Lulav does not apply at night: from the verse "Shiv'as
*Yamim*" (which incidentally is the verse used for the Gezeirah Shavah).
However, the Rabanan maintain that *two* verses (Shiv'As Yamim, ba'Yom) are
necessary to teach the the Lulav is not taken at night, since there are two
different Halachos with regard to the Mitzvah of Lulav that are only done
The first Halachah is that in the *Beis ha'Mikdash*, the Mitzvah is to hold
the Lulav for seven days. The second Halachah is that *outside* of the Beis
ha'Mikdash, the Lulav is held only the first day. Consequently, one verse
is needed to teach that the Lulav is not held at night in the Beis
ha'Mikdash, and another verse is needed to teach that it is not held at
night outside of the Beis ha'Mikdash. Rebbi Eliezer, though, maintains that
the Halachah that the Lulav is not held at night outside of the Beis
ha'Mikdash is derived from the Halachah with regard to inside the Beis
ha'Mikdash, and thus only one verse is needed to teach that it is not held