1) THE PURPOSE OF GIVING "HASRA'AH" TO THE SOTAH AND HER HUSBAND
QUESTION: The Mishnah states that Beis Din appoints two Talmidei Chachamim to escort the Sotah and her husband to the Beis ha'Mikdash. The Gemara explains that they must be escorted by two Talmidei Chachamim because if they are attempt to be together, the Talmidei Chachamim will give them proper Hasra'ah (warning).
When the Gemara says that the purpose of the Talmidei Chachamim is to give the couple Hasra'ah, it obviously does not mean simply that the Talmidei Chachamim must be escorts to warn the Sotah and her husband to stay apart, because it is not necessary to have Talmidei Chachamim for that purpose. Beis Din could appoint any two people and assign them to keep the man and woman apart. Obviously, the Hasra'ah in this case is the type of Hasra'ah necessary in order to administer a punishment. There are many Halachic details to the Hasra'ah, such as how close to the act it must be given and how the person who sins accepts the Hasra'ah (to which those who give the Hasra'ah must be witness), and therefore the Beis Din must send Talmidei Chachamim with the couple, because only Talmidei Chachamim are familiar with all of the laws of Hasra'ah.
For what punishment, though, is this Hasra'ah necessary? The Gemara in Yevamos (11b) states explicitly that only a Vadai Sotah is prohibited, by an Isur Lav and Malkus, from living with her husband, while a Safek Sotah is prohibited only by an Isur Aseh, "v'Nisterah v'Hi Nitma'ah" (Bamidbar 5:13)." (Although the Gemara here says that a Safek Sotah who is to drink the Mei Sotah is prohibited to her husband by a Lav, and the Gemara quotes the Lav mentioned in Yevamos (11b) with regard to a Vadai Sotah, Rashi does not mean that the same Lav applies equally to a Safek Sotah. Rather, he means that a Safek Sotah is prohibited because of a Safek Isur Lav, and a Safek Isur Lav is not punishable with Malkus.)
ANSWERS:
(a) TOSFOS in Yevamos (11b, DH Mai Nisterah; see also RASHBA cited by the Magid Mishneh, Hilchos Gerushin 11:14) explains that although the verse, "v'Nisterah v'Hi Nitma'ah," is only a Mitzvas Aseh, it nevertheless gives the status of a Vadai to a Safek Sotah (Sotah 28a). Consequently, any Chumra which applies to a Vadai Sotah applies to a Safek Sotah as well. Hence, just as a Vadai Sotah is punishable with Malkus, so, too, a Safek Sotah is punishable with Malkus because the Torah treats her like a Vadai.
(b) However, Tosfos elsewhere in Yevamos (69a, DH Ki Siheyeh) and in Sotah (28a, DH Mah Talmud Lomar) and many other Rishonim do not accept this approach. They write that an act of relations with a Safek Sotah is not punishable with Malkus (see also ROSH, cited in previous Insight). What, then, is the point of the Hasra'ah given to the couple?
RASHI explains that the point of the Hasra'ah is to inform the husband that if he lives with his wife, he will not be "Menukeh me'Avon" ("free of sin") and the Mei Sotah will not be able to determine whether his wife is innocent or guilty of adultery and, consequently, she will remain prohibited to him forever. Rashi means (as Tosfos writes in Yevamos 58a, DH Ela) that only when the husband sins b'Mezid (intentionally) is he considered not to be "Menukeh me'Avon." If, however, he sins b'Shogeg (unintentionally), the Mei Sotah will be effective. Rashi understands that the degree of intent necessary to render the act one of Mezid is the same degree of intent required to render a sinner liable for Malkus. This intent is determined by the presence of Hasra'ah from witnesses (see Sanhedrin 46a, where the Gemara explains that the purpose of Hasra'ah is to differentiate between an act of Shogeg and an act of Mezid).
According to Rashi, it is possible that the reason why the Mei Sotah is not effective when the man is not "Menukeh me'Avon" is that it is a punishment for his misdeed. He is no longer worthy of having the Mei Sotah determine whether his wife is permitted to him or not (and, consequently, she remains prohibited to him forever). Therefore, his act needs Hasra'ah in order to deserve this punishment.
Why, though, does Rashi and the other Rishonim not explain as Tosfos does, that the reason for this Hasra'ah is that the Torah makes a Safek Sotah like a Vadai Sotah (as the Gemara says explicitly)?
There are several possible reasons for why Rashi does not explain that this is the reason for the Hasra'ah. Rashi may understand that when the Torah considers a Safek Sotah to be like a Vadai Sotah, it does not give her the actual status of a Vadai Sotah. Rather, as Tosfos later (28a) explains, the Torah means that in the case of a Safek Sotah, the Safek Isur is stronger than an ordinary Safek Isur in that the Isur of a Safek Sotah is as strong as the Isur of a Vadai Sotah. However, it remains its own independent Isur, an Isur Aseh. The Isur Aseh of a Safek Sotah is a Vadai Isur, but it is still not the same as the Isur Lav of a Vadai Sotah.
Alternatively, even if Rashi accepts Tosfos' view that a Safek Sotah is like a Vadai Sotah, that status is not necessarily enough to warrant Malkus. As Tosfos himself writes, a Safek Sotah is like a Vadai Sotah only l'Chumra -- but the punishment of Malkus is a Kula because it permits the Beis Din to do an act that would otherwise be prohibited mid'Oraisa (because of the Lav of "Lo Yosif"). Tosfos, who rules that a Safek Sotah receives Malkus, apparently learns that at the moment that Beis Din rules that she is a Safek Sotah, she has the status of a Vadai Sotah and the punishment of Malkus that comes about afterwards is a punishment for living with a Vadai Sotah. That Malkus comes after Beis Din has already ruled that she has the status of a Vadai Sotah. (This is similar to the RAMBAM's principle that although Malkus cannot be administered based on the testimony of an Ed Echad (a single witness), nevertheless if an Ed Echad testifies that a certain piece of meat is not kosher, one who eats it afterwards (in front of two witnesses) will receive Malkus.)
A third answer is that Rashi may follow the view expressed by the RITVA in Makos (4a) that in order to administer Malkus there must be an Azharah (where the Torah explicitly states a Lo Ta'aseh). Hence, even if a Safek Sotah is considered like a Vadai Sotah, since there is no Azharah for the Isur in the Torah, the Isur is not punishable with Malkus.
2) WORDS NOT FIT TO BE HEARD
OPINIONS: The Mishnah (7a) states that the Sotah is told words "that are not fit for her to hear." The Gemara explains that she is told the stories of Reuven and Yehudah, both of whom sinned, admitted their sins, and repented for their sins. Why are these stories considered "not fit for her to hear"?
(a) RASHI explains that the point of telling her these stories is to convince her to confess her sin. When she hears about the Tzadikim who sinned and confessed their sins, she will be more willing to confess her own sin. When the Mishnah states that these stories are "not fit for her to hear," it means that comparing this woman with those great Tzadikim is inappropriate because their sins were different, and they admitted their sins and did complete Teshuvah, while this woman is still a suspected adulteress.
(b) The RAMBAM (in Perush ha'Mishnayos) gives the opposite explanation. The Sotah is told about terrible sins, such as the verse's account of Reuven's sin with the Pilegesh of his father, and the story of Yehudah who lived with his daughter-in-law. Although Reuven did not actually sin (Shabbos 55b), she is told the literal story, according to the way it is written in the verses, so that she will not be embarrassed to confess her sin (which is a lesser sin than the ones described by the verses in the stories of Reuven and Yehudah).
(c) The ME'IRI explains that the words in the Mishnah should be read together as one long phrase: "We tell her things that she is not able to hear [even when accompanied by] her entire family." The Mishnah means that we present her with a persuasive argument to confess her sin. The argument is so persuasive that even if her family members are present she will not be embarrassed to admit her guilt. Telling these stories do not disgrace her for the sin she committed, but rather these stories make her sin seem less significant (as the Rambam explains, as quoted above).
When the Mishnah says that these words are "not fit for her to hear," it means that she is not strong enough to withstand the persuasion to confess.
This is also the explanation of the RAMBAM in the Mahadura Basra of the Perush ha'Mishnayos (Kapach edition), and it seems to be the approach of the Rambam in Mishnah Torah (Hilchos Sotah 3:2) as well. The Rambam writes that we threaten the woman and try to persuade her when her husband is not present. The Acharonim ask what the Rambam's source for this ruling is; from where does he learn that the woman is threatened while the husband is not present (see KEREM NETA)? According to the Me'iri's reading of the Mishnah, the Mishnah is the source for the Rambam's ruling. The Mishnah says that we persuade her in such a way that even if her father's family is present, she will not be embarrassed to confess her sin. This implies that only her father's family is present, but her husband and his family are not present.

7b----------------------------------------7b

3) THE PURPOSE FOR BRINGING THE SOTAH TO THE "BEIS DIN HA'GADOL" IN YERUSHALAYIM
OPINIONS: The Mishnah (7a) states that the Sotah is brought to the Beis Din ha'Gadol of 71 Dayanim, in Yerushalayim. The Gemara derives this from a Gezeirah Shavah from Zaken Mamrei.
What exactly does the Beis Din ha'Gadol do with the Sotah? What part of the procedure of Sotah requires the Beis Din ha'Gadol?
(a) TOSFOS (DH Mah) explains that the Beis Din ha'Gadol threatens the woman and attempts to persuade her to confess her sin. The drinking of the Mei Sotah and the administering of the Shevu'ah do not need to be done in the presence of the Beis Din ha'Gadol.
Tosfos adds that since threatening the woman does not impede (Me'akev) the effectiveness of the Mei Sotah, b'Di'eved the entire process may be done without the Beis Din ha'Gadol.
(b) However, RASHI (DH Mena Hani Mili, and 7a, DH l'Sha'ar Mizrach) explains that the Sotah drinks the Mei Sotah in the presence of the Beis Din ha'Gadol. Rashi maintains that the entire process of Hashka'as Sotah (giving the Mei Sotah to the Sotah to drink) must be done in the presence of the Beis Din ha'Gadol in Yerushalayim.
Rashi here points out that no source is necessary for the requirement that she drink the Mei Sotah in front of an ordinary Beis Din of 23 Dayanim. The Gemara needs a source only for the requirement that she drink the Mei Sotah in front of the Beis Din ha'Gadol. Why does Rashi assume that it is obvious that without any source to the contrary, the Hashka'as Sotah would need to be done in the presence of an ordinary Beis Din of 23 Dayanim? Rashi apparently understands that the Hashka'as Sotah is a form of a punishment, and a punishment requires a Beis Din of 23 Dayanim. The Gemara teaches that a Beis Din of 23 Dayanim does not suffice, and the process of Hashka'as Sotah must be done in the Beis Din of 71 Dayanim.
Tosfos, on the other hand, maintains that the Hashka'as Sotah is merely a means of clarifying whether or not the woman sinned; it is not a punishment. Therefore, the Hashka'as Sotah does not need to be done in front of a Beis Din.