1) LEARNED FROM AN INFERENCE
QUESTION: Rav Dimi (20b) says in the name of Rebbi Yochanan that a person who swears that he will eat (or not eat) and then violates his Shevu'ah is guilty of transgressing the prohibition of "v'Lo Sishav'u vi'Shemi la'Shaker" (Vayikra 19:12), while a person who transgresses a Konam (Neder) violates the prohibition of "Lo Yachel Devaro" (Bamidbar 30:3). (See previous Insight.) Ravin disagrees with Rav Dimi. He quotes Rebbi Avahu in the name of Rebbi Yochanan as saying that the verse of "v'Lo Sishav'u vi'Shemi la'Shaker" (Vayikra 19:12) prohibits a Shevu'as Sheker l'she'Avar (swearing falsely about a past action). On the other hand, the prohibition against making a Shevu'as Sheker leha'Ba (an oath to do, or not to do, something in the future), is derived from "Lo Yachel Devaro" (Bamidbar 30:3).
Rav Papa asserts that Rebbi Avahu did not say this teaching explicitly, but rather Ravin deduced it from a statement which Rebbi Avahu made in a different context. Rebbi Yochanan taught that a person is punished with Malkus for making a Shevu'as Sheker because the verse of Shevu'as Shav (Shemos 20:7) teaches that the transgression against making a Shevu'as Shav is punishable with Malkus. The verse says "la'Shav" a second time in order to teach that a second type of Shevu'ah is also punishable with Malkus. Since the second type of Shevu'ah cannot be a Shevu'as Shav (which is already mentioned in the verse), it must be referring to a Shevu'as Sheker. Rebbi Avahu explains that the only Shevu'as Sheker to which Rebbi Yochanan can be referring is a Shevu'as Sheker l'she'Avar, and yet Rebbi Yochanan refers to such a Shevu'ah as a Shevu'as Sheker, implying that it is prohibited by the verse of "v'Lo Sishav'u vi'Shemi la'Shaker" (Vayikra 19:12) and not by the verse of "Lo Sisa Es Shem Hash-m... la'Shav" (Shemos 20:7), the verse that prohibits Shevu'as Shav.
Normally, when the Gemara writes that an opinion expressed in the Gemara was deduced from a different statement ("Michlala Itmar"), it is understood to be an unreliable teaching. The Gemara always asks what difference it makes that it was deduced from another statement, and the Gemara goes on to explain how the inference may have been incorrect (see, for example, Berachos 12a, Shabbos 40a, Yevamos 60b). In what way is the deduction from Rebbi Avahu's words here incorrect?
ANSWERS:
(a) The RITVA writes that the term "Michlala Itmar" here is used in a unique way. It does not mean that the deduction was incorrect, but rather that Rebbi Avahu's statement was not explicit. This is why the Gemara does not conclude by explaining what was incorrect about the inference from Rebbi Avahu's words.
(b) The CHASAM SOFER suggests that the term "Michlala Itmar" here may be interpreted in its normal manner. It is true that according to Rebbi Avahu, Rebbi Yochanan requires the second word "la'Shav" to teach that a Shevu'as Sheker l'she'Avar is treated the same way as a Shevu'as Shav. However, once we know that the second "la'Shav' refers to a Shevu'as Sheker l'she'Avar, we know that such a Shevu'ah indeed may be included in the prohibition of "Lo Sisa..." written in the beginning of the verse. (That is, "la'Shav" is not merely a Ribuy for Malkus, but rather it places Shevu'as Sheker l'she'Avar into the verse of "Lo Sisa.") Therefore, Rebbi Avahu might be expressing the same opinion as Rav Dimi, that Shevu'as Sheker l'she'Avar is learned from "Lo Sisa," as well as "Lo Sishav'u." Shevu'as Sheker leha'Ba is learned from "Lo Sishav'u," and "Lo Yachel Devaro" teaches Konamos (Neder), as Rav Dimi teaches in the name of Rebbi Yochanan. (The Gemara does not ask what is incorrect about making this inference from Rebbi Avahu's words, because the weakness of this inference is so obvious.)
This indeed is consistent with the ruling of the Rambam, who rules that both a Shevu'as Sheker l'she'Avar and a Shevu'as Sheker leha'Ba both included in the prohibition of "Lo Sishav'u."

21b----------------------------------------21b

2) "MUSHBA V'OMED ME'HAR SINAI"
QUESTION: The Gemara quotes the Mishnah later (22b) which teaches that if a person makes a Shevu'ah that he will not eat, and then he eats Neveilos (which the Torah prohibited before he made his Shevu'ah), he is punished for violating his Shevu'ah as well as for transgressing the Isur of Neveilos. The Gemara asks that he should not be punished for violating his Shevu'ah, because he is "Mushba v'Omed me'Har Sinai." An oath cannot take effect to enforce an act for which one is already bound by an oath. A person is considered bound by the Mitzvos as if he took an oath at Har Sinai to keep them.
Why does the Gemara use the words "Mushba v'Omed..." to explain why a Shevu'ah does not take effect on what the Torah prohibits? It should give the normal principle of "Ein Isur Chal Al Isur" as the reason for why the Shevu'ah does not take effect in such a case!
The same point may be made about the Gemara's statement that if a person prohibits an object with a Shevu'ah and then repeats the Shevu'ah, the second prohibition does not take effect because "Ein Shevu'ah Chal Al Shevu'ah" (Nedarim 18a). Why does the Gemara not say simply, "Ein Isur Chal Al Isur"? (NODA B'YEHUDAH OC 1:36; see also Insights to Nedarim 18:2.)
ANSWERS:
(a) The NODA B'YEHUDAH suggests that, apparently, the rule of "Ein Isur Chal Al Isur" applies only to what the Torah itself prohibits; it does not apply to what a person prohibits upon himself through a Shevu'ah.
The Noda b'Yehudah does not explain the basis for his hypothesis. What is the logical distinction between a Shevu'ah and any other Isur in the Torah? Perhaps he means that an ordinary Isur in the Torah does not address a particular person or a particular situation. It does not need to take effect when there is already another prohibition, and in fact the Torah does not intend for the second prohibition to apply when another prohibition is already in place. A Shevu'ah, however, is stated with the explicit intention that it apply to a particular person and to a particular situation. Since the one who swore did not intend for the Shevu'ah to be limited to what was not previously prohibited to him, perhaps it should apply even where a prohibition of the Torah (or another Shevu'ah) is already in force.
The Gemara therefore explains that since a Torah prohibition is also a form of Shevu'ah, a second Shevu'ah cannot take effect and reinforce it. (This logic may not apply to a Neder, since the prohibition created by a Neder must be based on the Torah's prohibition of Korban. Therefore, it does not depend on the person's specific intent any more than does the Isur of Korban. This is why Tosfos (20b, DH d'Chi) applies the rule of "Ein Isur Chal Al Isur" to a Neder.)
(b) The KOVETZ HE'OROS (#33) suggests that a Shevu'ah does not create an actual prohibition. Rather, when a person makes a Shevu'ah that he will do a particular act, he is asserting that such an act will certainly take place. If that act does not take place (that is, if he does not fulfill his Shevu'ah), then he has lied. He is obligated to fulfill his Shevu'ah simply in order to prevent himself from having lied retroactively. (For an in-depth discussion of the nature of the prohibition of a Shevu'ah, refer to Rav Dov Zupnik's online Audio Shi'ur to Shevu'os 22a.)
Accordingly, the Isur of Shevu'ah is not similar at all to any other Isur of the Torah, since it takes effect neither on a particular object nor on a particular act. Rather, it forces a person to act in a certain way to prevent himself from lying. The reason why an Isur cannot take effect where a previous Isur exists is because the second Isur adds no new dimension to the Isur that already exists (see Insights to 20b). A Shevu'ah, in contrast, does add a new dimension and does not simply reinforce the previously-existing Isur.
Both of these approaches, however, are not consistent with the words of the Rishonim who explicitly use the principle of "Ein Isur Chal Al Isur" when they discuss a Shevu'ah. (See, for example, the BA'AL HA'ME'OR, end of third Perek.)
(c) The AVNEI MILU'IM (#12) suggests that the logic of "Ein Isur Chal Al Isur" does apply with regard to a Shevu'ah. However, when the rule of "Ein Isur Chal Al Isur" is applied, normally the second Isur cannot obligate the transgressor to receive a second set of Malkus or a Korban, but, nevertheless, it does increase the strength of the prohibition. The Gemara in Yevamos (33b) explains that because the prohibition becomes stronger, the transgressor is considered a greater Rasha, and thus, when he is buried, he is buried among similar Resha'im.
The Gemara intends to teach that when a Shevu'ah is made to prohibit something that is already prohibited by the Torah, not only does the Shevu'ah not obligate a new set of Malkus or a Korban, but the Shevu'ah does not even strengthen the prohibition. That is, "Mushba v'Omed me'Har Sinai" is a more effective way of stopping the Shevu'ah from taking effect than "Ein Isur Chal Al Isur."
(The logic for this seems to be as follow. The Torah does not give a person the right to prohibit himself with a Shevu'ah from doing something which he is already prohibited from doing with a Shevu'ah ("Mushba v'Omed..."). The verses that discuss Shevu'ah teach that if the second Shevu'ah creates a new prohibition, or even adds a Chiyuv of Malkus or Korban to a pre-existing Shevu'ah, the second Shevu'ah should take effect. However, when the Shevu'ah creates no new obligation of any sort but merely strengthens a prohibition that already exists, no source teaches that the Torah recognizes such a Shevu'ah as binding. Consequently, because of the principle of "Ein Isur Chal Al Isur" -- which teaches that the Shevu'ah cannot create a Chiyuv of Malkus or Korban when an Isur Torah already exists -- one must conclude that a Shevu'ah made to prohibit something that is already prohibited by the Torah will not be valid.)
The Avnei Milu'im mentions a number of practical consequences of the fact that the Shevu'ah does not even strengthen the pre-existing Isur:
1. The obvious consequence is that a person who transgresses such a Shevu'ah is not buried among the more wicked Resha'im.
2. If a person is so ill that the doctors say that he will die unless he eats Neveilah, then he is permitted to eat Neveilah. What is the Halachah in a case in which the sick person previously prohibited himself with a Shevu'ah from eating Neveilah? Since a person can repeal a Shevu'ah through "She'eilah," the law of Piku'ach Nefesh does not permit a person to violate his Shevu'ah. If the normal rule of "Ein Isur Chal Al Isur" would apply, then the person would be required to perform "She'eilah" before he eats the Neveilah, in order to remove at least one of the Isurim. However, because of the principle of "Mushba v'Omed," the Shevu'ah will not take effect at all and it will not be necessary to do "She'eilah" in order to repeal the Shevu'ah.
3. The Gemara (24a) relates that according to Reish Lakish, even if the principle of Isur Kolel teaches that a second Isur which includes more than the first Isur takes effect, this rule does not apply to a self-created Isur such as a Shevu'ah. The Avnei Milu'im asserts that this is also based on the principle that "Mushba v'Omed" is more limiting that the principle of "Ein Isur Chal Al Isur." An Isur Kolel takes effect only because of the fact that the second Isur would exist even if it could not obligate the transgressor to receive Malkus; since the Isur creates Malkus with regard to other objects, the rule of Isur Kolel states that there will be Malkus as well for the Isur that was created on top of the pre-existing Isur. However, since the Shevu'ah does not create an Isur at all on what was previously prohibited, the principle of Isur Kolel will not apply.
4. The Avnei Milu'im suggests further that when the Gemara says "Mushba v'Omed me'Har Sinai" and "Ein Shevu'ah Chal Al Shevu'ah," its intention is to show that even if the Isur of the Torah and the person's Shevu'ah come into effect at the same time ("b'Vas Achas"), the Shevu'ah still does not take effect even though, normally, when two Isurim come into effect at the same time they do take effect. For example, if a person makes a Shevu'ah prohibiting himself from eating Neveilah, and after he makes the Shevu'ah his animal dies, then even though the animal becomes forbidden to him because of the Isur Torah of Neveilah and because of his Shevu'ah at the same time, the Shevu'ah does not take effect.
The logic for this seems to be similar to the logic mentioned above (in #3). The reason why two Isurim normally can take effect "b'Vas Achas" is that even if they would not create a Chiyuv of Malkus (because of "Ein Isur Chal Al Isur"), nevertheless the Isurim co-exist. However, because of the principle of "Mushba v'Omed me'Har Sinai" (or "Ein Shevu'ah Chal Al Shevu'ah"), the Shevu'ah itself cannot take effect if there is a pre-existing Isur. Therefore, even if the Shevu'ah and Isur take effect simultaneously, the Isur will take effect and the Shevu'ah will not take effect. (This might be true even according to those who disagree with Reish Lakish and maintain that a Shevu'ah does take effect through Isur Kolel.)
However, the Acharonim point out that the Gemara in Makos (22a) implies that even before the animal dies and becomes Neveilah, the Isur Torah was already in effect, and therefore the Isur of Shevu'ah should not take effect when the animal dies, even if the animal dies after the Shevu'ah was made (MISHNAS REBBI AHARON, Yevamos 19; SHI'UREI REBBI SHMUEL, Yevamos 32:270).
Moreover, the Acharonim ask that the approach of the Avnei Milu'im is not consistent with the RAMBAM (Hilchos Shevu'os 4:10), who apparently maintains that the second Shevu'ah does take effect to make a more severe Isur.

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