The Mishnah discussed cases of vows made in error, known as Nidrei Shegagot. For instance, if someone declared an item forbidden to themselves if they ate, but at the time of making the vow, they had forgotten they had already eaten, this is considered a mistake. Consequently, the vow is not binding. Similarly, if a person vowed that an item would be forbidden if they ate, and then later, when about to eat, they forgot about the vow, this is also a mistake, and the vow is not binding.
The same principle applies to an oath made in error, a Shevuah Bishgaga, which does not require annulment; it is permissible and not binding. What constitutes a Shevuah Bishgaga? The Gemara presents a scenario involving two scholars. One states, "I swear that this is what I heard from Rav," while the other declares, "I swear that I heard the opposite in the name of Rav." Each scholar, at the moment of taking their oath, genuinely believes they are speaking the truth. The Rishonim explain that even if they later consulted Rav, and he clarified who was correct, they would not need to seek annulment for their oaths. This is because at the time of the oath, each believed their statement to be true. The novelty of this case is that even when someone immediately contradicts you, your oath is still considered an error. The Gemara could have presented simpler cases of mistaken oaths, similar to the Mishnah's examples of eating. By introducing this scenario, the Gemara teaches a greater novelty: even with immediate contradiction, if one genuinely believes their statement, it's considered an error, and the oath is not binding.
The Gemara continues by revisiting the last case of the Mishnah: a man sees people eating figs and declares, "These figs are forbidden to all of you, like a sacrifice." He then realizes his father or brother is among them. The Mishnah presented a dispute: Beit Shammai stated that the father is permissible, but everyone else remains forbidden. Beit Hillel, however, argued that once the vow is broken for one person, it is broken for all. Beit Hillel's reasoning is that if the man had known his father was present, he would not have made the vow in that manner. The Gemara brings a similar case involving Rabbi Akiva. Rabbi Akiva holds that if a man vows to fast every day of the year but later realizes he cannot fast on Shabbat or holidays, this realization can serve as an opening for annulment. If he had known from the outset that he couldn't fast on Shabbat or holidays, he would not have made the vow. In such a scenario, Shabbat and holidays become permissible, and everything else remains forbidden. This illustrates the concept that if a part of the vow is annulled, the entire vow is annulled.
Rabbah then offers an interpretation of the Mishnah, stating that all opinions (both Beit Shammai and Beit Hillel) agree on a specific scenario. If, when the man reconsiders his vow, he states, "Had I known my father was among those eating figs, I would have said the exact same words, but I would have stipulated 'except for my father'," then everyone agrees that his father is permissible, and everyone else remains forbidden. This is a case of "establishing one's words" (Ma'amid Devarav), where he is not changing his original terminology but merely adding a stipulation. The logic, as explained by the Ran, is that this is not considered a partial annulment that would void the entire vow. Since he is asserting that his father was never intended to be included in the original declaration, he is not retracting his words but clarifying their initial scope. Therefore, his father is permissible, as he was never truly part of the vow, while everyone else remains forbidden.
The Gemara then clarifies the scenario where Beit Shammai and Beit Hillel actually dispute. This is a case where the man initially said, "All of you are forbidden." Then, upon realizing his father was present, he said, "Had I known my father was part of the group, I would have changed my terminology. Instead of saying 'all of you are forbidden,' I would have said 'this one and this one are forbidden, and my father is permissible.'" This is termed "changing one's words" (Mishaneh). In this case, Beit Shammai would maintain that the father is permissible, and the others are forbidden, aligning with the Rabbanan's view in Rabbi Akiva's fasting case, where only the specific exceptions are annulled, not the entire vow. Beit Hillel, however, would contend that the entire vow is annulled, meaning neither the father nor anyone else is bound by it. Their reasoning is twofold: first, there was a total mistake in the initial phrasing that seemed to include the father; second, the man regrets using the general term "all of you" because he doesn't even want to imply, for a moment, that his father was included. Since he is so particular about the language, it indicates a fundamental error in the original vow, leading to its complete annulment.
To summarize Rabbah's position:
In the Ma'amid case (where he clarifies, "I would have said the same words, just with a stipulation"), Rabbah holds that everyone agrees: the father is permissible, and everyone else is forbidden. The logic is that the father was never truly part of the original vow.
In the Mishaneh case (where he states, "I would have changed my terminology"), Rabbah posits that Beit Shammai and Beit Hillel disagree. Beit Shammai says the father is permissible, and others are forbidden. Beit Hillel says everyone is permissible, based on the principle that if part of a vow is annulled, the whole vow is annulled.
The Gemara then presents a different interpretation by Rava (with an Aleph). Rava argues that in the Mishaneh case, where the man says, "Had I known my father was in the group, I would have changed my terminology to specify 'this one and this one are forbidden,' because I wouldn't even want to imply for a second that my father was included," then everyone agrees that the entire vow is permissible. This is because he is changing two things: the language and the exclusion of his father, indicating a fundamental error. Therefore, according to Rava, the dispute between Beit Shammai and Beit Hillel is actually in the Ma'amid case. In this scenario, where the man says, "I would have said the same words, 'all of you are forbidden,' but I would have added 'except for my father'," Beit Shammai would say the father is permissible and others forbidden, while Beit Hillel would say everyone is permissible. This dispute, according to Rava, hinges on the principle of "following the first expression" (Tfos Lashon Rishon) versus "following the last expression" (Tfos Lashon Aharon), a concept derived from laws of animal sacrifices. Beit Shammai follows the first expression, meaning the initial general vow stands, and the father's exclusion is merely a clarification. Beit Hillel follows the last expression, viewing the clarification as a fundamental change that annuls the entire vow.
The Gemara then introduces a Baraita (a teaching from the Mishnaic period) that presents cases where Rabbi Akiva's principle (that if part of a vow is annulled, the whole vow is annulled) applies.
Case 1: "I will not benefit from any of you." If one of them becomes permissible, all become permissible.
Case 2: "I will not benefit from this one or this one." If the first becomes permissible, all become permissible.
Case 3: "If the last one becomes permissible, the last one is permissible, but all others are forbidden."
The Gemara asks how Rabbah (with a Heh) can reconcile this Baraita with his view. Rabbah explains that the first two cases (the Reisha) refer to a Mishaneh scenario. For example, in Case 1, the man initially said "I will not benefit from any of you." Then, upon realizing his father was present, he said, "Had I known, I would have stipulated 'except for my father'." This is a Mishaneh case because he would have changed his terminology to avoid even a momentary inclusion of his father. According to Rabbah, in a Mishaneh case, everyone agrees that the entire vow is annulled, making it consistent with Rabbi Akiva's principle. Similarly, Case 2, where he initially said "this one and this one," but then would have preferred to say "all of you except for my father" (because the specific listing implies he might eventually include his father), is also a Mishaneh case, leading to complete annulment. The Baraita's phrase "if the first becomes permissible, all become permissible" means that once the father is permissible, everyone else is too.
The Gemara then challenges Rava (with an Aleph), asking how he can reconcile the Baraita. Rava's view is that the dispute between Beit Shammai and Beit Hillel is in the Ma'amid case. The Baraita's first two cases, if interpreted as Ma'amid, would align with Rava's understanding of Beit Hillel's view (that all are permissible). However, the Gemara then attempts to interpret Case 2 as a Mishaneh case. If it's a Mishaneh case, then according to Rava, everyone (including Beit Shammai) agrees that all are permissible. If so, why does the Baraita present these as cases where Rabbi Akiva's principle applies, implying a specific ruling, when it should be a universally agreed-upon outcome?
The Ran clarifies that Rava needs two distinct cases in the Baraita to illustrate the concept of Shinui (change of words) in both directions: from specific to general, and from general to specific. This demonstrates that any such change constitutes a legal reversal. However, in a Ma'amid case, where the language remains the same, one case would suffice. Therefore, Rava is compelled to interpret the second case as a Mishaneh to show a novelty. But this creates the problem: if it's Mishaneh, everyone agrees, so why is it presented as a specific ruling of Rabbi Akiva?
Rabbah (with a Heh) then counters Rava, asking how Rava's interpretation of the Baraita makes sense, specifically regarding Case 3. According to Rava, Case 3 is a Ma'amid case, where the man says, "All of you are forbidden," but then clarifies, "except for my father." In this Ma'amid scenario, Rava holds that Beit Shammai says the father is permissible and others forbidden, while Beit Hillel says all are permissible. The Baraita's ruling for Case 3 is "if the last one is permissible, the last one is permissible, but all others are forbidden." This aligns with Beit Shammai's view. However, Rabbah points out a terminological inconsistency: in the first two cases (where all are permissible), the father is referred to as "the first" (Rishon) to become permissible. But in Case 3, where only the father is permissible, he is called "the last" (Aharon). Why the inconsistent terminology?
Rava then presents his final interpretation of the Baraita to resolve all questions. He explains that Case 1 is indeed a Ma'amid case. Rava would interpret it as a Ma'amid where the man says "all of you are forbidden" but clarifies "except for my father." This fits Rava's view of the Ma'amid dispute, where Beit Hillel would say all are permissible. Rabbah, conversely, would learn Case 1 as a Mishaneh case, where the man would have changed his words entirely to avoid offending his father, leading to complete annulment. So, Case 1 fits both their views, each according to their own understanding of Ma'amid or Mishaneh.
Cases 2 and 3, however, are a completely different scenario. They describe a vow where each person's prohibition is made dependent on the previous one ("this one, and this one, and this one"). If the man then annuls the vow for the first person in the chain, the entire chain breaks, and everyone becomes permissible (Hutar Rishon Hutar Kulam). But if he annuls the vow for the last person in the chain, only that last person becomes permissible, and everyone before them remains forbidden (Hutar Aharon HaAcharon Mutar V'chulan Asurim). This explains the varying use of "first" and "last" in the Baraita's terminology; it refers to their position in the chain of interdependence, not to Ma'amid or Mishaneh. Thus, the Baraita is not a challenge to either Rabbah or Rava.
The Gemara then raises another challenge against Rava, focusing on his interpretation of the Ma'amid case. Rava maintains that in a Ma'amid case, Beit Hillel holds that all are permissible, based on the principle of Tfos Lashon Aharon. The challenge comes from a story involving Rabbi Meir. A man vowed, "I will not eat onions," explaining that onions are bad for the heart. When told that onions from Kufri are good for the heart, Rabbi Meir permitted him to eat all onions. The Gemara clarifies the details: the man said, "Had I known that Kufri onions were good for the heart, I would have said, 'All onions are forbidden, except for Kufri onions'." This is a Ma'amid case, where he intended to use the same language but add a stipulation. According to Rabbi Meir, the entire vow became permissible. This contradicts Rava's understanding, who aligned Rabbi Meir with Beit Shammai's view of Ma'amid, which would split the vow (Kufri onions permissible, others forbidden). Rabbi Meir's ruling implies that in a Ma'amid case, the entire vow is annulled, which is Beit Hillel's position. This would mean Rabbi Meir does not hold like Beit Shammai (and Tfos Lashon Rishon) in Nedarim, thus undermining Rava's entire framework for the Ma'amid dispute.
The Gemara responds by reinterpreting the onion case. It states that the man did not say, "I would have said 'all onions except Kufri'." Rather, he said, "Had I known that Kufri onions were good for the heart, I would have said, 'This onion and this onion are forbidden, but Kufri onions are permissible'." This is a Mishaneh case, where he would have changed his terminology. In a Mishaneh case, everyone agrees that the entire vow is annulled, making Rabbi Meir's ruling consistent with all opinions, not just a specific one. Therefore, the onion case does not pose a difficulty for Rava's understanding of the Ma'amid dispute. Thus, Rava's position remains unchallenged.