1) PROOF THAT THE CHACHAMIM ARE EMPOWERED TO UPROOT A TORAH LAW
QUESTIONS: The Gemara continues its attempt to prove that the Rabanan have the authority to uproot a law written in the Torah. The Gemara cites a Beraisa which discusses Tashlumei Terumah -- compensation paid by a Zar for deriving personal benefit from Terumah. In the case of the Beraisa, a Zar ate Terumah Tehorah and intentionally paid Terumah Teme'ah to the Kohen as compensation. Rebbi Meir maintains that his payment is not valid, "Ein Tashlumav Tashlumin." The Chachamim disagree and rule that his payment is accepted, but he must pay a second time with Terumah Tehorah.
The Gemara proves from Rebbi Meir's opinion that the Rabanan have the authority to uproot a law written in the Torah because, mid'Oraisa, a payment of Terumah Teme'ah is a valid payment, and yet the Rabanan disqualified it. The enactment of the Rabanan goes so far as to invalidate a Kidushin which the Kohen performed with the payment, and the woman whom he betrothed is not Mekudeshes (and she may marry another man and does not need a Get from the Kohen).
TOSFOS (DH Azil) questions this proof:
(a) Why does the Gemara infer that the Rabanan have the authority to uproot a Torah law from the fact that the Kidushin which the Kohen performed with the Terumah Teme'ah does not take effect? There is a far more obvious proof that the Rabanan may uproot a Torah law. Normally, the fruit paid as compensation by a Zar for inadvertently eating Terumah becomes Terumah mid'Oraisa itself. Here, Rebbi Meir states that mid'Rabanan the payment is not valid, and thus the decree of the Rabanan prevents it from becoming Terumah. That is, the Rabanan removed the status of Terumah from the payment even though mid'Oraisa it is Terumah! (This case is the same as the case cited by the Gemara in the beginning of the Sugya on 89a.)
(b) The Gemara's proof from the fact that the Kidushin does not take effect is problematic. In cases of monetary matters, the principle of "Hefker Beis Din Hefker" applies; even if the Rabanan are not authorized to uproot Torah law, they do have the power to render a person's property ownerless, as the Gemara earlier teaches. Why does the Gemara prove from the fact that the Rabanan took away the payment from the recipient (the Kohen) that the Rabanan have the power to uproot a Torah law? "Hefker Beis Din Hefker" is different and does not involve uprooting a Torah law!
ANSWERS:
(a) TOSFOS answers that the Gemara cannot prove that the Rabanan have the authority to uproot a Torah law from the fact that the payment does not become Terumah according to Rebbi Meir, because Rebbi Meir does not say outright that it does not become Terumah. He says merely that the payment is not a valid payment, which means that the payment is returned to the payer, in contrast to the view of the Rabanan that the payment is kept by the recipient (and the payer must pay a second time). When the payment is returned to the payer, however, perhaps it retains the status of Terumah; the fact that it is not a valid payment and is returned does not mean that it loses the status of Terumah which it obtained at the moment it was given to the Kohen.
(b) TOSFOS answers the second question by explaining that the principle of "Hefker Beis Din Hefker" does not apply in this case. The Rabanan do not utilize their power of "Hefker Beis Din Hefker" to take away money from a recipient (in this case, the Kohen) which legally belongs to him and he did nothing to deserve losing it. In this case, it was the payer, and not the recipient, who did something wrong. Hence, the Rabanan did not apply "Hefker Beis Din Hefker," and the only reason why they took away the payment from the Kohen must be that their enactment has the ability to uproot the Torah law.
This answer of Tosfos is problematic for several reasons.
1. The MAHARSHA (in MAHADURA BASRA) asks that taking away the payment of Terumah Teme'ah from the Kohen in no way harms the Kohen or causes him a loss. On the contrary, taking it away is to his advantage. In order to give him a payment of a higher quality (Terumah Tehorah), the Rabanan took away the Terumah Teme'ah which he received originally so that the Zar will pay again with Terumah Tehorah. Since it is to the Kohen's benefit to have the Rabanan take away the Terumah Teme'ah from his possession, why did the Rabanan not apply "Hefker Beis Din Hefker" in this case? (See ARUCH LA'NER.)
2. REBBI AKIVA EIGER points out that the Gemara seeks to prove that Rebbi Meir maintains that the payment is not valid, and that the Rabanan maintain that the money is taken away from the Kohen. If "Hefker Beis Din Hefker" is not the reason for why the payment is taken away from the Kohen, then it must be that it is taken away because of the Rabanan's authority to uproot a Torah law. However, the same reason why the Rabanan do not utilize "Hefker Beis Din Hefker" in this case should apply to their authority to uproot a Torah law: just as they do not apply "Hefker Beis Din Hefker" so as not to harm the Kohen, they also should not take away his payment by uprooting the Torah law which says that the payment is valid! Conversely, if they have grounds to uproot a Torah law and revoke the payment even though they thereby harm the Kohen, they should also be able to take away the payment from him by applying "Hefker Beis Din Hefker"!
3. The Gemara earlier contradicts the assertion of Tosfos that the principle of "Hefker Beis Din Hefker" does not apply when it would involve taking away something from a person who did nothing wrong. The Gemara earlier says that in the case of a married Ketanah who dies, the Rabanan apply "Hefker Beis Din Hefker" to take away her estate from the father and give it to her husband even though the father did nothing wrong in that case.
Perhaps these questions may be answered as follows.
1. If the intent of the Rabanan was to make the Zar pay the Kohen the full amount with Tahor fruit, they did not need to take away the fruit that he already paid to the Kohen. They could have required merely that the Zar continue to pay the Kohen more until his payment equals the value of the Terumah Tehorah that he ate. There was no need to take away the Terumah Teme'ah that was already paid to the Kohen, and thus they did not apply "Hefker Beis Din Hefker" in this case.
(One might ask that in the case of a person who separates Terumah from Tamei produce to exempt Tahor produce (89a), the Gemara suggests that the Rabanan uprooted the status of Terumah to remind its owner to separate Terumah a second time from Tahor produce, and they did not merely require him to separate additional Terumah to make up for the loss in value. However, that logic cannot be applied here, because making the Kohen return the payment to the Zar will not ensure that the Zar will pay the Tashlumei Terumah in full, since returning the payment causes no harm to the Zar. Uprooting the status of Terumah in the case of one who separates Terumah from Tamei produce for Tahor produce ensures that the owner will separate Terumah again, because he cannot eat the rest of his produce until he does so (for it is Tevel mid'Oraisa). Moreover, uprooting the Terumah in that case ("Min ha'Tahor Al ha'Tamei") is done for the sake of enforcing the laws of Terumah and not for the benefit of the Kohen, as will be explained below.)
2. Perhaps Rebbi Akiva Eiger's question may be addressed as follows. Tosfos does not mean that Rebbi Meir maintains that the Rabanan required only that the Kohen return the Terumah Teme'ah and they did not rescind its status as Terumah. Rather, Tosfos means that one might have thought that this is what Rebbi Meir means (in the words of Tosfos, "Havah Matzi l'Meimar").
The Gemara proves that this is not the intention of Rebbi Meir from the fact that he says "Ein Tashlumav Tashlumin," the payment is not valid, which implies that the fruits paid to the Kohen cannot be used for Kidushin. Why should the Kohen not be able to use the money? The enactment of the Rabanan is for his benefit, so that he will receive the full value of the Terumah that the Zar ate. What point is there in taking away the money from him, either through "Hefker Beis Din Hefker" or through uprooting a Torah law?
The Gemara teaches that it must be that Rebbi Meir means something else when he says that the payment is not valid. He must mean that the Rabanan indeed revoked the status of Terumah from the payment such that the Tamei fruit which the Zar gave to the Kohen does not become Terumah in the first place. Consequently, the Kohen must give it back because is was given to him by mistake. It is not a valid Tashlumei Terumah; the Zar gave it to him only because he thought it was Tashlumei Terumah. Since, if the status of Terumah is uprooted, the payment was not the Kohen's in the first place, the Rabanan are not directly taking away anything directly from the Kohen by uprooting the status of Terumah from the Tashlumim. In this sense, uprooting the status of the Tashlumei Terumah is identical to the case in which the Rabanan uprooted the status of Terumah that was taken from Tamei produce to exempt Tahor produce (89a). In that case, too, if the owner gives the Kohen the invalid Terumah the Kohen must return it. He indirectly loses Terumah as a result of the enactment because what was separated improperly remains Tevel and does not have the status of Terumah at all.
(This idea may also be expressed as follows: If the enactment of the Rabanan was that the fruit does not become Terumah in the first place, this indicates that it was not enacted simply for the benefit of the Kohen (so that he should receive the full value of what the Zar ate). Rather, it was enacted to protect the honor of Terumah. By paying Tashlumei Terumah with fruits that are Tamei (and thus less valuable than the fruit he ate), the Zar degrades the honor of the Terumah that he ate, and that is why the Rabanan enacted that the payment is not valid. If this enactment would cause the Kohen to lose money indirectly (and perhaps even directly), the loss would not stop the Rabanan from enacting such an enactment since they deemed it important to ensure that proper respect is given to Terumah.)
3. The reason why the Rabanan applied "Hefker Beis Din Hefker" and took away the Ketanah's inheritance from the father was because he willingly married off his daughter to a man while she was a Ketanah. He freely chose to give her away, knowing that he would thereby lose the right to inherit her. Therefore, the Rabanan applied "Hefker Beis Din Hefker" to take away the money that he otherwise would have been entitled to receive. In the case of the Tashlumei Terumah, however, the Kohen has no choice in the matter, and thus the Rabanan do not take away his money through "Hefker Beis Din Hefker." (Moreover, the Gemara assumes at this stage that the enactment was made only for the Kohen's own benefit, and thus the Rabanan certainly are not interested in causing harm to the Kohen through their enactment.) (M. Kornfeld)

90b----------------------------------------90b

2) DONNING A FOUR-CORNERED GARMENT WITHOUT TZITZIS
OPINIONS: The Gemara states that the Rabanan may override the Mitzvah of Tzitzis in a garment made of linen through a "Shev v'Al Ta'aseh" -- a passive infraction (by requiring that a person not do something), and not through a "Kum v'Aseh," a positive action.
Why is donning a four-cornered garment that has no Tzitzis considered a case of "Shev v'Al Ta'aseh"? When the person dons a four-cornered garment that has no Tzitzis, he does an act ("Kum v'Aseh") of donning a garment without Tzitzis.
(a) TOSFOS (DH Kulhu) and other Rishonim explain that the Torah's commandment to wear Tzitzis entails placing Tzitzis on a garment which one is already wearing. Before he dons the garment, there is no Mitzvah to put Tzitzis on it (according to the opinion that the Mitzvah of Tzitzis is a "Chovas Gavra" and applies only to a garment which is worn and not to a garment which is stored in a box). Therefore, when one places upon his body a four-cornered garment that has no Tzitzis, he transgresses no Mitzvah. He transgresses the Mitzvah only after the garment is upon him and he still refrains from tying Tzitzis onto it. This transgression, however, is through "Shev v'Al Ta'aseh," since the Mitzvah obligates him to tie Tzitzis to the garment and he passively refrains from doing so. (If he would don a four-cornered garment with no Tzitzis and then immediately begin to tie Tzitzis onto it, he would transgress no Mitzvah at all.)
The TOSFOS HA'ROSH quotes the RITZBA who says that according to this understanding, if one of the four Tzitziyos falls off of the garment on Shabbos, one is permitted to wear the garment even l'Chatchilah. Donning the four-cornered garment without Tzitzis is not a transgression of the Mitzvah, and after he dons it he is unable to tie Tzitzis to it because of the Melachah of tying on Shabbos. (He is not permitted to walk into a Reshus ha'Rabim or Karmelis while wearing the garment, because he is considered to be carrying the other three Tzitzis since they do not qualify as the Mitzvah without the fourth Tzitzis. Nevertheless, he is permitted to wear the garment inside his house, and even to don it l'Chatchilah. See also SHITAH MEKUBETZES to Menachos 37b, #4.)
(b) The SHA'AGAS ARYEH (#32) challenges the explanation of Tosfos and his ruling.
1. As Tosfos himself points out, the blessing which one recites upon donning a garment with Tzitzis -- "l'His'atef ba'Tzitzis" -- implies that the Mitzvah is to actively wrap oneself in a garment with Tzitzis, and not merely to place Tzitzis on the garment once it is already being worn.
2. The Gemara in Shabbos (132b) teaches that a Mitzvas Aseh overrides a Lo Ta'aseh only in a manner "similar to the way Tzitzis overrides the Lo Ta'aseh of Kil'ayim." This general rule includes the condition that the Mitzvas Aseh must be fulfilled at the very moment the Lo Ta'aseh is transgressed in order for it to override the Lo Ta'aseh. According to Tosfos, however, the Lo Ta'aseh of Kil'ayim is transgressed before the Mitzvah of Tzitzis is fulfilled. Kil'ayim is transgressed through an act of "Kum v'Aseh," by actively donning a garment of Kil'ayim (as Tosfos proves from the Gemara in Berachos 20a). The Mitzvah of Tzitzis is fulfilled only after one has already donned the garment. Consequently, one transgresses the Isur of Kil'ayim before he fulfills the Mitzvah of Tzitzis, and thus the Mitzvas Aseh of Tzitzis should not override the Lo Ta'aseh of Kil'ayim.
3. The Sha'agas Aryeh suggests further that any transgression which must be preceded by an initial action is considered a transgression of "Kum v'Aseh" even though no action is done at the time the actual transgression is committed. Accordingly, even if the Mitzvah of Tzitzis does not take effect until the garment is upon the person, wearing a four-cornered garment without Tzitzis still should be considered uprooting a Mitzvah through "Kum v'Aseh," since the transgression must be preceded by an initial action of donning the garment. He proves this from examples of Torah prohibitions which are transgressed passively (with no action), but for which Malkus nevertheless is administered (even though Malkus is administered only for actively transgressing a prohibition -- "Lav she'Yesh Bo Ma'aseh").
For example, the Gemara in Nazir (40a) relates that if a Nazir sat in a closed box and was carried into a cemetery (according to the opinion that a box effectively separates between him and the Tum'ah), and another person came and removed the cover of the box, the Nazir transgresses the prohibition against becoming Tamei and he receives Malkus if he does not leave immediately. In that case, the initial action of entering the cemetery -- even though done in a permissible manner -- renders the act a "Lav she'Yesh Bo Ma'aseh." Similarly, the donning of a four-cornered garment should render the transgression one which is accomplished through a "Kum v'Aseh."
The Sha'agas Aryeh therefore suggests a different answer to the question of Tosfos. He writes that any time an act is forbidden not because of what is done, but because of what is not done, it is called a "Shev v'Al Ta'aseh."
In the case of one who wears a four-cornered garment without Tzitzis, the wrongful act is not that the person is wearing a garment without Tzitzis, but that he has not tied Tzitzis to the garment. Although the act of donning the four-cornered garment without Tzitzis is forbidden, what causes the prohibition is the fact that he did not tie Tzitzis to the garment. This is in contrast to the Isur of Kil'ayim, which one is considered to transgress through "Kum v'Aseh" when he dons a garment that contains a forbidden mixture of Kil'ayim not because he fails to remove the garment from upon him, but because he has actively donned a garment of Kil'ayim.
Similarly, the Isur which prohibits a Nazir from entering a cemetery states that a Nazir may not be in a cemetery (as that is how the Torah describes the Isur) and not that a Nazir must stay outside of a cemetery. For this reason, the Isur which prohibits a Nazir from entering a cemetery is considered a "Kum v'Aseh" and Malkus may be administered.
(According to this reasoning, one certainly is prohibited from donning a four-cornered garment without Tzitzis, even on Shabbos.)