QUESTION: The Gemara discusses the source for the Halachah that a false
prophet, a "Navi Sheker," is judged for death by a court of seventy-one
judges. Rebbi Yosi bar'Rebbi Chanina learns that the source is a Gezeirah
Shavah from the law of Zaken Mamrei, since the Torah uses mentions the
concept of "Hazadah" ("Asher Yazid," "Asher Ya'aseh b'Zadon") with regard to
both. Just like the Zaken Mamrei is Chayav Misah only when he rebels against
the ruling of the Sanhedrin of seventy-one judges, so, too, the Navi Sheker
is judged by a court of seventy-one judges. The Gemara questions this
source, asking that the phrase "Asher Ya'aseh b'Zadon" is mentioned only
with regard to the obligation to kill the Zaken Mamrei, and the law is that
a Zaken Mamrei is judged for death by only twenty-three judges, and not by
seventy-one! Hence, we have no source that a Navi Sheker is to be judged by
seventy-one, but rather he should be judged by twenty-three based on this
Reish Lakish, therefore, says that the source is a different Gezeirah Shavah
from the law of Zaken Mamrei. The word "Davar" is mentioned both with regard
to the requirement to kill a Navi Sheker, and with regard to the act of
rebellion of the Zaken Mamrei (which must take place with a Beis Din of
The Gemara asks, though, that if that is the source for the requirement to
judge a Navi Sheker with seventy-one judges, then we should also use the
other Gezeirah Shavah of "Hazadah" to teach *back* to Zaken Mamrei from Navi
Sheker that a Zaken Mamrei must be judged for death by seventy-one judges
(and not just by twenty-three)! The Gemara answers that the Tana of our
Mishnah learned the Gezeirah Shavah of "Davar," but he did not learn the
Gezeirah Shavah of "Hazadah." Why did he learn one Gezeirah Shavah and not
ANSWER: RASHI explains that a Talmid is permitted to expound a Gezeirah
Shavah only when that Gezeirah Shavah was passed down to him from his rebbi.
He must have a tradition to learn that Gezeirah Shavah. The Tana of our
Mishnah had received a tradition only to expound the Gezeirah Shavah of
"Davar," but not of "Hazadah." The Tana could not learn a Gezeirah Shavah
which he did not receive from his rebbi.
What is the reasoning behind this rule? Why can one Talmid not learn a
Gezeirah Shavah from his friend, who learned it from his rebbi? If his
friend has such a tradition from Har Sinai through his rebbi, then why may
the Talmid of a different rebbi not accept it?
TOSFOS in Shabbos (97a) asks this question. The Gemara there says that Rebbi
Akiva learned a certain Gezeirah Shavah, while Rebbi Yehudah differed in
opinion because he did not receive from his teachers a tradition to learn
such a Gezeirah Shavah. Tosfos asks why does Rebbi Yehudah not receive the
tradition for that Gezeirah Shavah from Rebbi Akiva? Tosfos answers that
each Tana had a tradition of how many Gezeirah Shavahs there were in the
Torah. Since Rebbi Yehudah had already accounted for all of his Gezeirah
Shavahs, he could not just add another one to the list. Rebbi Akiva, on the
other hand, either had one more Gezeirah Shavah in his number of Gezeirah
Shavahs, or he did not have in his count a certain Gezeirah Shavah which
Rebbi Yehudah did have in his count (see MAHARAM there).
To further understand the intention of Tosfos, we must analyze the words of
Tosfos in Sukah (11b, DH Lekichah). Tosfos there states that even though the
Rabanan learn certain Halachos from a Gezeirah Shavah of "Kichah," they do
not learn the Gezeirah Shavah which Rebbi Yehudah there learns of
"Lekichah." What is Tosfos telling us that we did not already know? We
already know from many Gemaras that not all of the Tana'im had the same
traditions with regard to Gezeirah Shavahs!
It seems that Tosfos is telling us that the process of handing down a
Gezeirah Shavah from rebbi to student did not involve handing down an entire
Derashah with the specific Halachos learned from the Gezeirah Shavah.
Rather, what was passed down was that a specific terminology can be used for
a Gezeirah Shavah, while the Halachos for which it can be used were *not*
taught. Consequently, when a Talmid saw that the Torah uses such terminology
in two places, and it seems to be indicating a connection, that Talmid would
then derive a Halachah through the Gezeirah Shavah on his own. Tosfos now
points out that we should not think that these terminologies are flexible.
Even though the Rabanan learn a Gezeirah Shavah with the phrase "Kichah,"
they never received a tradition to learn the terminology "Lekichah" as a
Gezeirah Shavah. Therefore, they cannot learn Rebbi Yehudah's Gezeirah
Shavah (based on ARUCH LA'NER; see RASHASH for further analysis).
This, too, seems to be the intention of Tosfos in Shabbos. Each Tana had a
tradition of how many terminologies one could use to learn a Gezeirah
Shavah. Once they had this tradition, they could never add a different
(b) The MARGOLIYOS HA'YAM, however, questions this answer of Tosfos from the
Gemara in Pesachim (66a). The Gemara there states that the B'nei Beseirah
did not want to accept a Gezeirah Shavah from Hillel until he exclaimed that
he had heard it directly from his teachers, Shemayah and Avtalyon. Why,
though, did this change their minds? According to the explanation of Tosfos,
how could the B'nei Beseirah now accept the Gezeirah Shavah of Hillel if
*they* did not have such a tradition? He answers by quoting many early
sources that teach that there is another type of Gezeirah Shavah. This type
is used when one is certain that something is true but does not have an
explicit source (see NIMUKEI YOSEF, Bava Kama, beginning of Perek 8).
Alternatively, it is a different type of Derashah which is in the format of
a Gezeirah Shavah format (HAFLA'AH). Therefore, the B'nei Beseirah thought
that Hillel's Gezeirah Shavah was this second type of Gezeirah Shavah. When
he told them that it was a genuine, standard Gezeirah Shavah, they then
agreed to accept it. The Margoliyos ha'Yam states that this is the case as
well in our Gemara and in other Gemaras. One Tana does not accept a Gezeirah
Shavah because he suspects that it might be the weaker form of Gezeirah
Shavah, which he does not have to accept. However, if he is told by the
disputing Tana that his rebbi explicitly taught it as a genuine Gezeirah
Shavah (as in the incident with Hillel), then the Tana would accept it. (Y.