THOUGHTS ON THE DAILY DAF
brought to you by Kollel Iyun Hadaf of Har Nof
Rosh Kollel: Rav Mordecai Kornfeld
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1) THE DIFFERENCE BETWEEN "BEREIRAH" AND A "TENAI"
QUESTION: The Gemara proves that Rebbi Yehudah does not hold of "Bereirah"
from the Beraisa of Ayo. Ayo states in the name of Rebbi Yehudah that one
may make a conditional Eruv only by stipulating that if the Chacham comes
to one side or the other side of the town, the Eruv will be to that side.
On the other hand, one may not make an Eruv by stipulating that if two
Chachamim come to each side of the town, he reserves the right to choose
the side on which his Eruv will take effect. In such a case the Eruv does
not work, because in order to work the principle of Bereirah has to be
utilized, and Rebbi Yehudah does not hold of Bereirah.
The Gemara asks that in both cases -- including the first case -- one is
utilizing Bereirah! Why, then, is the Eruv in the first case valid and in
the second case it is not valid? The Gemara answers in the name of Rebbi
Yochanan that the first case is discussing a situation where the Chacham
has already arrived, before Shabbos, at one side of the town. The
fulfillment of the condition later on Shabbos is not determining
retroactively where the Eruv took effect at the onset of Shabbos, but
rather it is merely clarifying the reality that existed at the onset of
Shabbos, and thus the Eruv is valid.
Why did the Gemara not suggest a simple difference between the two cases of
Ayo? Perhaps even if one stipulates "if the Chacham comes from the east
then my Eruv is to the east," the Eruv is valid, since it involves no more
than a normal case of stipulating a "Tenai" (condition). It is comparable
to giving a woman a conditional divorce by saying, "If you do such and
such, this Get will be a valid Get." In such a case, when the Tenai is
fulfilled, the Get becomes valid retroactively. However, when the person
says, "If two Chachamim come on both sides of the town, I will choose
tomorrow where I want my Eruv to take effect retroactively," Bereirah is
involved (since it is not merely a matter of a choice of "yes" or "no," but
of a choice of "yes, here" or "yes, there") and therefore the Eruv is not
(a) A Tenai works only because it is within the *ability* of one of the
parties involved to fulfill the condition, and because it was the
*intention* of the person who made the conditional statement that the
condition be fulfilled (RASHI Gitin 25b DH u'Lechi). That is to say, since
he plans on fulfilling the condition, the event contingent upon the
condition takes effect *immediately*, even before the Tenai has been
fulfilled. If the Tenai ends up not being fulfilled, then the event that
was contingent upon it is uprooted *retroactively*. A Tenai can *uproot* an
event retroactively even without resorting to Bereirah, but it cannot cause
it to *take effect* retroactively without resorting to Bereirah.
That is not the situation in Ayo's case. In the case of making an Eruv, the
condition (that the Chacham comes from this side) is not in the hands of
the person who made the statement to fulfill, nor does he wish it to be
fulfilled (i.e., he has no particular interest for the Chacham to come from
that side as opposed to the other side). Because of this, it is considered
a case of Bereirah and not a case of Tenai.
(b) The RAMBAN in Gitin (25b) argues with Rashi and explains that a case of
Tenai exists when there are two possibilities -- either the event will
occur or it will not occur. On the other hand, when trying to make
something happen which can occur in one of several ways, then it is not a
Tenai but a question of Bereirah. The case of the Eruv dependent on the
Chacham coming to one of two sides is such a case and therefore it involves
Bereirah. The event -- the Eruv taking effect -- is going to happen in one
of two places; the arrival of the Chacham will determine where the Eruv
Still, why is the case of the Chacham a case of Bereirah? We can view it as
*two* completely separate conditions: (1) If the Chacham comes to the east,
then the Eruv will be to the east, and if he does not come to the east,
then there will be no Eruv to the east. (2) If the Chacham comes to the
west, then the Eruv will be to the west, and if he does not come to the
west, then the Eruv will not be to the west. (So asks REBBI AKIVA EIGER in
a Ma'arachah on Eruvin.) TOSFOS here (DH Mai Shena) in fact asks this
question on the explanation of the Ramban.
Apparently, the Ramban maintains that the two Eruvei Techumim cannot be
viewed as two independent events. Rather, a single event is taking place
(making an Eruv), and there are two possibilities as to how it will take
place (to the east or west). The reason for this is that one cannot make
two Eruvs to be Koneh Shevisah in two places (since a person lives only in
one place at a time). Therefore, when the person adds that if the Chacham
comes to the other side his Eruv will be to that side, it is viewed as an
addendum to his first condition, rather than a separate condition.