What is the Gemara's question? Rebbi Shimon ben Elazar says clearly that
another person *can* accept a Get Shichrur for the Eved Kena'ani! Does that
not show clearly that the Eved can appoint a Shali'ach? And if we say that
the reason why another person can accept a Get for the Eved Kena'ani is
because of the principle of Zechiyah ("Zochin l'Adam"), then what difference
does it make if the Eved can or cannot make a Shali'ach? In any case, the
other person should be able to be Koneh the Get for the Eved through
Zechiyah! If the Gemara is discussing a case in which the Eved, upon
receiving the Get, complains that he never wanted it, then both in the case
of Zechiyah and in the case of Shelichus, he should not acquire the Get,
because he shows that he is not interested in being free and that it is a
Chov (detriment) to him! (RASHBA, RITVA; see TOSFOS DH Mahu.)
(a) The RASHBA and other Rishonim prove from our Sugya that Zechiyah and
Shelichus are two separate concepts. That is why the Gemara asks whether the
Eved Kena'ani can make a Shali'ach, even though we know that he can acquire
the Get through Zechiyah. The Rashba, Ritva, and Tosfos (in his first
answer) explain that our Gemara means to say that if an Eved cannot appoint
a Shali'ach, then when he tells someone to receive his Get through
Shelichus, and the master gives the Get Shichrur to that person saying that
"I want you to accept this Get the way the Eved wants you to accept it,"
then indeed the Get will not be valid if the Eved does not have the ability
to appoint a Shali'ach.
The logic for this is that even though the person could have received the
Get for the Eved through Zechiyah, once he chooses to take it through
Shelichus and not through Zechiyah he does not acquire the Get for the Eved
through Zechiyah. Since the Eved cannot make a Shali'ach, the person also
cannot acquire the Get for the Eved as a Shali'ach, and thus the Eved is not
freed.
(b) The RITVA cites RABEINU YITZCHAK HA'LEVI, who agrees that Zechiyah does
not work through Shelichus, but who answers the question in a different
manner. The practical difference of whether or not an Eved can appoint a
Shali'ach is when an Eved appoints a Shali'ach to accept his Get, and the
Shali'ach accepts it and brings it back to the Eved, and then the Eved says
that he changed his mind and did not want the person to accept the Get for
him at the time that he accepted it. If the person acquires the Get for the
Eved through Zechiyah, then when the Eved changes his mind and says that he
did not want a Get, he will not be freed because it turns out that it was
not a Zechus (benefit) for him, but rather it was a Chov. However, if an
Eved can make a Shali'ach, and the person accepted the Get for the Eved
through Shelichus, then even though the person cannot acquire the Get
through Zechiyah, nevertheless he acquired the Get for the Eved through
Shelichus, since the Eved did not explicitly annul the appointment of the
Shali'ach but merely lost interest in being freed. Since he did not annul
the Shelichus, the Shali'ach is able to acquire the Get for the Eved,
because the Eved consented to acquire it at the time of the appointment of
the Shali'ach, and it makes no difference that the Eved was not interested
in the Get at the time that the Shali'ach actually received it, as long as
the person he sent is still a Shali'ach. (See the SHITAH NODA L'MI who gives
a similar explanation).
(c) RASHI in Gitin (9b) and TOSFOS in Kesuvos (and other places) write that
Zechiyah *does* work through Shelichus. How, then, do they understand our
Gemara which says that an Eved Kena'ani might not be able to make a
Shali'ach because he cannot receive the Get himself, and nevertheless
someone else can receive the Get for him?
TOSFOS and the TOSFOS HA'ROSH explain that when the Gemara suggests that an
Eved cannot make a Shali'ach, it maintains that the reason another person
can accept a Get for the Eved is neither because of Shelichus *nor* because
of Zechiyah. How, then, can someone accept a Get for the Eved? It seems that
Tosfos understands that Rebbi Shimon ben Elazar is arguing with the logic of
Rava and Abaye (on 23a) who differentiate between Kesef and Shtar. He holds
that just like Kesef can be accepted by someone else for the Eved, and it
does not have to be accepted by the Eved himself, so, too, the Shtar can be
accepted by someone else, since the master can free the Eved against his
will. It makes no difference that the Shtar is not taken by the master but
by the other person; the other person can still free the Eved against his
will without relying on Shelichus.
Tosfos writes that according to this understanding, the Gemara's question is
as follows. Is the reason Shtar works according to Rebbi Shimon ben Elazar
by being received by someone else ("Shtar Al Yedei Acherim") because the
Shtar does not have to be accepted by the Eved but can be accepted by
anybody? Or does a "Shtar Al Yedei Acherim" work because of Zechiyah and
Shelichus, and therefore if the Eved insists that he does not want to
receive the Shtar, he cannot be freed against his will? The Tosfos ha'Rosh
notes that this also appears to be the way Rashi learns the Gemara (in DH
k'Ishah, and DH O Dilma). The Gemara's question is how does "Shtar Al Yedei
Acherim" work according to Rebbi Shimon ben Elazar.
(d) RASHI, however, adds that there is another practical difference if an
Eved can appoint a Shali'ach. Rashi (DH O Dilma) writes that if an Eved
Kena'ani cannot make a Shali'ach, then when Rebbi Shimon ben Elazar says
that a "Shtar Al Yedei Acherim" works to free the Eved, he means "either
that the master can be Mezakeh to him the Shtar through another person, *or*
that another person could take the Get without the Eved's knowledge." The
second half of Rashi's statement is clear -- if the Eved cannot make a
Shali'ach, then a "Shtar Al Yedei Acherim" must work without the Eved's
consent, but against his will, like Tosfos writes. However, what does Rashi
mean in his first explanation, when he says that the master could be Mezakeh
to the Eved a Get through giving it to another person, even though Shelichus
does not work? If Zechiyah works through Shelichus, then how could Zechiyah
work if Shelichus here does not work? (See BIRKAS SHMUEL, #11, DEVAR SHMUEL,
IMREI BINYAMIN.)
It seems that Rashi himself was questioning whether Zechiyah works through
Shelichus or not. In his first explanation, he assumes that the question of
the Gemara is whether Zechiyah works through Shelichus. If an Eved can make
a Shali'ach, then we have no reason to propose that Zechiyah is a separate
form of freeing the Eved; rather, it will work through the assumption that
the Eved would have made the person a Shali'ach. If the Eved *cannot* make a
Shali'ach, then we must conclude that Zechiyah does not work through the
mechanics of Shelichus, and that is why the Eved can go free through a
"Shtar Al Yedei Acherim." The conclusion of the Gemara is that Zechiyah
works through Shelichus. (See RITVA at the end of the Sugya.)