1) PROOF THAT "YADAYIM SHE'EINAM MOCHICHOS" ARE NOT "YADAYIM"
OPINIONS: The Gemara attempts to refute Abaye who maintains that "Yadayim she'Einam Mochichos" are Yadayim. It cites a Beraisa which discusses the case of a person who declares, "Harei Hu Alai" -- "Behold this item is upon me." The Beraisa says that such a declaration is a Yad l'Korban and the Neder takes effect. The Beraisa implies that if the person does not say "Alai" ("upon me"), the Neder does not take effect because the phrase "Harei Hu" alone is a Yad she'Eino Mochi'ach and such a Yad does not suffice to make a Neder.
The Gemara rejects this proof and asserts that the phrase "Harei Hu" alone is not even a Yad she'Eino Mochi'ach for a Neder, because the person might have intended with those words to make the item Hefker or to give it to Tzedakah. A Yad she'Eino Mochi'ach, however, is considered a valid Neder, as Abaye maintains.
The Gemara does not accept this support for Abaye because "the Beraisa says 'it is a Yad l'Korban'." What does this mean? How do these words of the Beraisa refute Abaye's rebuttal?
(a) The RAN's understanding of the Gemara is based on his own view that there are two types of primary Neder: a Neder one makes by saying that the item is prohibited ("this item is Asur"), and a Neder one makes by comparing the object to Hekdesh ("this item is like a Korban"). When a person does not compare the object to Hekdesh, the object -- although it becomes Asur -- does not undergo an inherent change in status (that is, it attains no degree of Hekdesh). If a person says merely that the object is Asur, it has merely an Isur Cheftza upon it; it does not undergo a change of status. Abaye's refutation of the proof against him from the Beraisa is that "Harei Hu" implies that there is a change of status in the object and not just an Isur on the object. (Although some maintain that "Yesh Me'ilah l'Konamos" (35a), that might apply only when the person makes a Neder with Hatfasah.) Accordingly, "Harei Hu" implies Hefker or Tzedakah, which are both inherent changes of status. The Gemara responds to Abaye that "Harei Hu" alone -- although it cannot be a Yad for a Neder without Hatfasah -- should be a Yad for actually making the object Hekdesh (or a Yad for a Neder with Hatfasah), because it changes the status of the object, just like Hefker or Tzedakah.
(b) According to the ROSH, Abaye's rebuttal is based on the wording of the Beraisa. When the Beraisa says "it" is a Yad l'Korban, the Beraisa implies that one portion of the sentence "Harei Hu Alai" is a Yad. Obviously, the word "Alai" alone is not a Yad, for it is meaningless when said alone. Rather, the phrase "Harei Hu" must be a Yad. Although "Harei Hu" is a Yad, a Neder is created only when the person says, "Harei Hu Alai." Hence, a Yad she'Eino Mochi'ach ("Harei Hu") is not a Yad.
(c) TOSFOS and the TOSFOS YESHANIM explain that the phrase in the Beraisa, "because it is a Yad for a Korban," implies that the declaration of "Harei Hu Alai" is a Yad Mochi'ach for a Korban. The Beraisa's emphasis that the Yad works only because it is a Yad Mochi'ach implies that a Yad she'Eino Mochi'ach does not create an Isur and is not a Yad.

6b----------------------------------------6b

2) "YAD L'KIDUSHIN"
QUESTION: The Gemara discusses whether the laws of Yados apply to Kidushin, Pe'ah, Tzedakah, Hefker, and Beis ha'Kisei, just as they apply to Nedarim.
What is the Gemara's doubt whether Yad can make Kidushin take effect? In the case of a Neder, unless the Neder is verbally articulated (as opposed to a thought in one's mind; Shevuos 26b) the Neder does not take effect. A Yad might not suffice to make a Neder since it is not a fully articulated statement, and therefore a verse is needed to teach that a Yad creates a Neder. In contrast, there is no source that says that Kidushin must be created through speech, and thus Yad certainly should work.
ANSWERS:
(a) RAV BARUCH BER LEIBOWITZ (in BIRKAS SHMUEL, beginning of Kidushin) cites the words of his mentor, RAV CHAIM SOLOVEITCHIK. He explains that Kidushin indeed must be made with speech. The source for this requirement is the verse, "Ki Yikach Ish Ishah" (Devarim 22:13), which teaches that the man must perform an act of taking the woman (as opposed to the woman performing an act to take the man; Kidushin 2b). This verse teaches that not only must the man give to the woman Kesef or a Shtar for Kidushin, but he also must make clearly communicate through his speech or his action that he is betrothing her with Kidushin.
(b) There is an important difference between the Kinyan of Kidushin and all other Kinyanim. An ordinary Kinyan takes effect even when no witnesses see the Kinyan. As long as both the buyer and seller consent, the Kinyan takes effect. In contrast, Kidushin must be done in the presence of witnesses, and it is not valid at all without them (Kidushin 65b). The witnesses cause the Kidushin to take effect; their presence is an intrinsic part of the Kidushin process. Consequently, if the man does not clearly articulate that his intent with this act is to betroth the woman with Kidushin, the witnesses do not know for certain that an act of Kidushin is being performed and, consequently, the Kidushin does not take effect. It does not suffice that witnesses watch the event; they also must know that they are witnessing an act of Kidushin. Even if both the man and woman later state that they had intent for Kidushin to take effect, the Kidushin is not valid unless the husband announced his intent at the time the act of Kidushin was performed.
Why, though, does the Halachah of Yados not suffice to reveal his intent? When one's words are a Yad Mochi'ach they reveal his intent, even though he makes no explicit statement about his intent. The answer is that a Yad Mochi'ach does not make one's intention absolutely clear. If his partial statement would be absolutely clear, it would not be a Yad Mochi'ach but rather an explicit expression of intent (it would just be a different form of expression). Every Yad -- even a Yad Mochi'ach -- contains some aspect of ambiguity. The Halachah of Yados teaches that although his words do not make his intent absolutely clear, they are clear enough that his intent is considered to have been stated explicitly. Therefore, with regard to Kidushin, his statement is considered clear enough for the witnesses to know his intent only if the Torah teaches that a partial statement is judged as a clear expression of his intent.
3) THE DIFFERENCE BETWEEN KIDUSHIN AND GERUSHIN WITH REGARD TO "YADOS"
QUESTION: Rav Papa asks whether or not the Halachah of Yados can make Kidushin take effect. The RAN points out that Yados certainly works for Gerushin. Since the Yad of the Gerushin is accompanied by the act of giving over the Get, it is considered more than just a Yad Mochi'ach; it is an "Ikar Mochi'ach" -- the circumstances clearly reveal his intent. In the case of Kidushin, however, no act accompanies the man's statement ("v'At"). He does not even give a Perutah to the woman when he says the statement of Yad.
REBBI AKIVA EIGER (in Gilyon ha'Shas) asks that according to the Ran's explanation of the difference between Gerushin and Kidushin, the Gemara's proof --- that Rav Papa maintains that a Yad may be used for Kidushin -- is difficult to understand. Rava Papa asked Abaye about Shmuel's opinion that a Yad she'Eino Mochi'ach is a valid Yad for Kidushin. Shmuel ruled that when a man gives a Shtar to a woman and says to her, "Harei At Mekudeshes," words which are a Yad she'Eino Mochi'ach, the Kidushin takes effect. From the fact that Rav Papa questioned Shmuel's ruling that a Yad she'Eino Mochi'ach is valid for Kidushin implies that Rav Papa agrees that a Yad Mochi'ach is valid for Kidushin. However, in Shmuel's case, the man's words were accompanied by an action (the giving of a Shtar) which clearly showed his intent, and thus it is not a case of Yad at all but a case of "Ikar Mochi'ach." According to the Ran, how can the Gemara prove from there that Rav Papa maintains that Yad works for Kidushin?
Moreover, why does the Ran maintain that giving a Get is considered an act that clarifies the man's intent? The Get itself does not contain a clear statement of divorce because he is not required to write the words "Mina'i" ("from me") or "v'Dein" ("with this [Get]") according to the Chachamim (see 5b), since they maintain that a Yad she'Eino Mochi'ach suffices. Why, then, does the action of giving the Get to the woman add more clarity about his intent?
ANSWER: The reason why the act of giving a Get is considered an act that shows his intent is that the act informs us of the two missing facts: who is divorcing the woman, and with what he is divorcing her (with speech or with a Shtar). Since this man has been her husband until now and it is he who now hands her the Get, it is obvious that he is the one divorcing her. It is also obvious that the divorce is effected by the giving of the Get, since the Get he gives to her contains the words of Gerushin.
In contrast, when a man gives a woman money for Kidushin and says "Harei At Mekudeshes" ("behold you are betrothed") but does not say "Li" ("to me"), it is unclear who is marrying this woman. It is possible that another man appointed this man as his Shali'ach to give the woman money for Kidushin on his behalf. Since the man has no previous relationship with the woman, his act of giving her money does not clarify whether he is the groom or another man is the groom. In the case of divorce, however, the man who gives her the Get was married to her until now, and thus it is obvious that he is the one divorcing her with the Get and he is not acting as a Shali'ach on behalf of another man. (See AVNEI MILU'IM 27:1.)