1) "BECOMING PROHIBITED TO THE ONE WHO MADE HER PROHIBITED TO THE OTHER"
QUESTION: The Gemara seeks a case that fits the description of a man who lives with a woman who is prohibited to him, "and that man causes her to become prohibited to the one who made her prohibited to him in the first place." The Gemara suggests that this case refers to a Sotah who, after defying her husband's warning not to seclude herself with another man ("Stirah"), has relations with her husband (which is prohibited once she has become a Sotah). The act of prohibited relations with her husband causes her to become prohibited "to the one who made her prohibited [to her husband]" in the first place -- the Bo'el (the suspected adulterer).
The Gemara rejects this suggestion. What causes the Sotah to become prohibited to the Bo'el is not the prohibited act of relations between her and her husband. Rather, she is prohibited to the Bo'el even if her husband does not have relations with her, but instead gives her a Get or refuses to let her drink the Mei Sotah. Hence, it is inaccurate to say that it is the prohibited act of relations with her husband which causes her to become prohibited to the Bo'el.
What was the Gemara's initial intention when it suggested that when the husband lives with his Sotah wife, he prohibits her to the Bo'el? The Bo'el is prohibited to her even before the husband lives with her; once she has secluded herself with him, she becomes prohibited to both her husband and the Bo'el! In what way did the Gemara assume that living with her husband makes her prohibited to the Bo'el?
ANSWERS:
(a) TOSFOS explains that although the Bo'el is prohibited to the Safek Sotah, if she drinks the Mei Sotah and verifies her innocence she will become permitted to him. Once the husband lives with her, however, he no longer is "Menukeh me'Avon" and thus the Mei Sotah is not effective in determining the innocence of his wife. Accordingly, living with his wife causes her to become prohibited permanently to the Bo'el by depriving her of the ability to vindicate herself through drinking the Mei Sotah. This is the Gemara's intention in its initial assumption that the prohibited act of relations with her husband causes the Bo'el to become prohibited to her; it causes the Bo'el to become more prohibited to her than he was until now (i.e. permanently prohibited, and not just temporarily prohibited).
However, Tosfos questions this explanation. Why does the Gemara say that even if the husband merely declares that he does not want his wife to drink the Mei Sotah, he also causes her to become prohibited to the Bo'el? His refusal to give her the Mei Sotah now does not mean that she will never be able to prove her innocence. Perhaps her husband will change his mind and decide to give her the Mei Sotah to drink, at which time she will be able to prove her innocence. The possibility remains, therefore, that the Bo'el will become permitted to her.
Tosfos suggests a novel ruling based on this question. Tosfos suggests that if a husband says that he does not want his wife to drink the Mei Sotah, he may not change his mind. He is given only one opportunity to let her drink the Mei Sotah. Once he forfeits that opportunity, he may not bring her to the Beis ha'Mikdash to drink the Mei Sotah.
This novel proposal is problematic. As Tosfos himself points out, there is no source for such a law. Moreover, if this is the intention of the Gemara, the Gemara should not need to mention that her husband may prevent her from drinking the Mei Sotah in one of two ways -- by giving her a Get, or by declaring that he does not let her drink the Mei Sotah. The Gemara does not need to add that he can prevent her from drinking the Mei Sotah by giving her a Get; giving a Get is essentially the same as refusing to let her drink, and they are not two distinct ways of preventing her from drinking the Mei Sotah.
(b) RASHI makes no mention of the requirement that the husband be "Menukeh me'Avon" in order for his wife to be allowed to drink the Mei Sotah. ("Menukeh me'Avon" is the rule that Tosfos invokes to explain why the husband may not have his wife drink the Mei Sotah once he has had relations with her after she became a Sotah.) Rashi apparently follows his own view as expressed elsewhere (58b and 85b; see Insights there). Rashi maintains that there is a Tana who does not agree with the requirement that the husband be "Menukeh me'Avon" in order to have his wife drink the Mei Sotah. Rather, even after he lives with his wife he may give her the Mei Sotah to drink. Several Sugyos seem to follow the opinion of that Tana.
Accordingly, the Gemara here means that the husband is able to give the Mei Sotah to his wife even after he lives with her, in which case the original question returns: Why does the Gemara initially assume that when the husband lives with her, he causes her to become prohibited to the Bo'el? She already is prohibited to the Bo'el because she is a Safek Sotah!
The Gemara must mean that in a normal case of a Safek Sotah, when the husband does not live with his wife wrongfully, it is assumed that he plans to give her the Mei Sotah so that her innocence will be proven and she will become permitted to him again. An additional consequence of proving her innocence is that she becomes potentially permitted to the Bo'el. When, however, the husband has relations with her before her innocence is proven, he shows no regard for the fact that she is a Sotah and that he has no intention to give her the Mei Sotah to drink. Consequently, she remains prohibited to the Bo'el. The fact that her husband lives with her and shows that he does not care that she is a Sotah establishes a Chazakah that he will not give her the Mei Sotah. In that sense, he prohibits her to the Bo'el by having relations with her.
When the Gemara rejects the suggestion that it is the husband's act of relations which prohibits her to the Bo'el, because "even if he says, 'I will not give her to drink,' and even if he divorces her" she is still prohibited to the Bo'el, the Gemara means that she is prohibited to the Bo'el merely by virtue of her status as a Safek Sotah, without any act on the part of her husband. The husband's act does not create a prohibition to the Bo'el.
"Even if he divorces her" and permits her to all other men in the world, the Bo'el may not marry her, even if her husband did not live with her after she became a Sotah. "Even if he says, 'I will not give her to drink'" means that even if the husband dies without agreeing to give her the Mei Sotah, and she now becomes permitted to the rest of the world, she is still prohibited to the Bo'el. (See Rashi, end of DH Iy Neima.)
Consequently, according to Rashi (in contrast to Tosfos' understanding of the Gemara), the Gemara provides no proof that a husband may not change his mind when he declares that he does not want his wife to drink the Mei Sotah. (The Gemara also provides no proof that the husband may not give her the Mei Sotah to drink after he divorces and remarries her; see Tosfos to 85b, DH ul'Rebbi, and Insights there.) The Gemara merely says that if he does not give her the Mei Sotah to drink and, as a result, she does not prove her innocence, she becomes prohibited to the Bo'el simply because of her initial act of Stirah with him. The fact that her husband had relations with her and shows that he does not intend to give her the Mei Sotah does not create any new prohibition to the Bo'el; it just shows that he does not plan to give her the opportunity to become permitted. That is why the Gemara rejects the suggestion that the Bo'el is "the one who made her prohibited to him (the husband) in the first place." (M. Kornfeld)

95b----------------------------------------95b

2) THE LENIENCY OF THE PROHIBITION OF "ESHES ISH"
QUESTION: The Gemara seeks a case that fits the description of a man who lives with a woman who is prohibited to him, "and that man causes her to become prohibited to the one who made her prohibited to him in the first place." Rava concludes that this statement refers to the case of an "Eshes Ish." When a man lives with another man's wife, he causes her to become prohibited to her husband -- who was the one who made her prohibited to every other man in the first place (by virtue of marrying her).
The Beraisa (95a) derives a Kal v'Chomer from that case: if, in the case of a relatively less severe prohibition like "Eshes Ish," the man who has prohibited relations with the woman causes the person who created the prohibition in the first place (i.e. her husband) to become prohibited to her, then certainly in the case of a more severe Isur like "Achos Ishto," when the man has prohibited relations with the woman (his wife's sister), the person who caused the prohibition in the first place (his wife) should become prohibited to him.
The Gemara challenges the logic of the Kal v'Chomer. The Isur of "Eshes Ish" is clearly more severe than the Isur of "Achos Ishto" in many ways. The Gemara answers that the Isur of "Eshes Ish" is less severe in the sense that it is possible to remove the Isur even in the lifetime of the one who causes the Isur (the husband): the Isur of "Eshes Ish" is removed when her husband gives her a Get. In contrast, the Isur of "Achos Ishto" cannot be removed during the lifetime of the one who causes the Isur (the wife), because a man is never permitted to marry the sister of his wife during his wife's lifetime. (Only after his wife dies may he marry her sister.)
The Gemara's answer is problematic. When the Gemara earlier seeks a case that fits the description of "Ne'esar ha'Osrah," it rejects the possibility that it refers to the Isur of "Machzir Gerushaso" or to the Isur of "Yevamah la'Shuk." The Gemara gives various reasons for why those Isurim are not more lenient than the Isur of "Achos Ishto." One reason is that in the case of "Yevamah la'Shuk," the woman herself is "Nitma ha'Guf"; it was the woman herself who did something wrong and thereby caused her husband to become prohibited to her, while in the case of "Achos Ishto" it is the sister who sinned ("Nitma"), thereby making her sister prohibited to her husband. Another reason why the case of "Yevamah la'Shuk" is more stringent is that the Isur of "Yevamah la'Shuk" prohibits the woman to all men in the world, while the Isur of "Achos Ishto" prohibits the woman to only one man (her sister's husband). For this reason, the Gemara says that "Yevamah la'Shuk" cannot be called a "more lenient" Isur than the Isur of "Achos Ishto."
Why, in the Gemara's conclusion here, does the Gemara now assert that the Isur of "Eshes Ish" is less severe because it can be removed during the life of the one who makes her prohibited (the husband)? Why does the Gemara ignore all of the other objections which it raised earlier against making a Kal v'Chomer from "Yevamah la'Shuk" and from "Machzir Gerushaso"? Those objections also apply to making a Kal v'Chomer from the Isur of "Eshes Ish." (TOSFOS DH Ela)
Another difficulty is that the Isur of "Yevamah la'Shuk" is also able to be permitted in the lifetime of the one who causes her to prohibited (the Yavam); the Yavam can permit her to marry anyone else by performing Chalitzah with her! Why does Rava say that the Beraisa refers specifically to an "Eshes Ish"? The Beraisa could also refer to a "Yevamah la'Shuk," whose prohibition is more lenient than "Achos Ishto" because it can be removed during the lifetime of the Yavam!
ANSWER: The TOSFOS HA'ROSH answers in the name of the RIVA that in the case of an "Eshes Ish," the fact that she can become permitted in the lifetime of her husband is such a significant leniency that it overrides any of the other stringent laws that may apply to her (such as the fact that the Isur is punishable with Chenek, it is a case of "Nitma ha'Guf," and it is "Isurah b'Rov").
If this leniency overrides all of the stringencies, why does the Gemara not say the same thing about the Isur of "Yevamah la'Shuk"?
The answer is that the Isur of "Yevamah la'Shuk" is only an Isur Lav. The fact that an Isur Lav is able to become permitted in the lifetime of the one who causes the Isur is not such a significant leniency over the Isur of "Achos Ishto." As an Isur Lav, the Isur of "Yevamah la'Shuk" is not as severe and thus can be removed, while the Isur of "Achos Ishto" cannot be removed because it is an Isur Kares.
In contrast, the fact that the Isur of "Eshes Ish" -- which is an Isur Chenek, and more severe than an Isur Kares -- nevertheless can be removed during the lifetime of the one who causes the Isur shows that the Isur is much less severe than the Isur of "Achos Ishto," despite the fact that "Achos Ishto" is only an Isur Kares. This is why it is only in the case of the Isur of "Eshes Ish" that the fact that the Isur is removable during the life of the one who causes it demonstrates the relatively lower degree of severity of that Isur.