Explanation: The Gemara's question that this is obvious is because the previous case is also, "I will not eat from you." This is evident from the fact that the Gemara does not ask that the first case is obvious.

Implied Question: One cannot ask that being that we know the case, "if I will not eat" why do we need the case in the first part of the Mishnah, "that I will not eat from you?"

Answer: The Mishnah says this case, and also this case (two different ways of saying the same thing).

Question: Why don't we just ask him what he had in mind (as Shevuos are known to depend on the mindset of the person making the Shevuah)?

Answer #1: It is possible that he said that he had in mind that whatever the meaning was of what he said.

Answer #2: Alternatively, the case is where he forgot what he was thinking at the time.

Observation: The Gemara in Nedarim (16a) explains why Rav Ashi does not agree with Abaye.

Opinion #1: Rashi explains that if he says "Isar on me this loaf" it is as if he swore about this loaf. If he went back and said this about another loaf, it is as if he included the second loaf in the prohibition of the first.

Question #1: This is difficult. Later, the Beraisa states, "What is the Isar stated in the Torah? It is upon me etc." It does not say, "Isar this loaf on me."

Question #2: Additionally, Rashi's explains that when the Gemara discusses "Isur Isar," it means what is the law regarding a prohibition of this Isar? If you say the usage of Isar means an oath etc., meaning that you can show from a Pasuk that it is like he is making an oath and he is therefore liable to bring a Korban if he transgresses this oath, so too this prohibition etc. This is difficult. This implies that the Tana is coming to teach us the law of Isar, and is actually not teaching us anything, as he is doubtful regarding the law of using one oath to make a second oath.

Question #3: Additionally, it is not the way of the Mishnah or Beraisa to remain in doubt regarding whether one is liable or not for something.

Question #4: Additionally, what does the Gemara mean later when it says, "And he goes according to his reasoning?" Abaye here is doubtful, but later it is obvious to him that it is like he said an oath.

Question #5: Additionally, in all of the Sefarim we have the text, "He is like he said an oath and he is liable" [with a Vav]. According to Rashi, it should say, "He is liable" without saying "and" [without a Vav].

Opinion #2: Rabeinu Tam explains that the term "Mivta" stated in the Torah is a term of oath, that a person swears by saying "Mivta" as explained by Rashi as well. However, the term "Isar" stated in the Torah is not an oath where a person forbids himself from something using the term "Isar." Rather, the Torah is discussing where a person grabs onto another oath. He swears properly that he cannot have a certain loaf, and then he says, "It is upon me not to eat this (second) loaf just as I cannot eat this (first) loaf." This is the concept of Isar mentioned in the Pasuk.

This is also how Abaye understands the Beraisa. The prohibition of the concept of Isar is that if you make something forbidden using another oath, meaning that he prohibited it by equating it to a loaf that he had prohibited to himself by making an oath, it is like he has said an oath. (He has therefore prohibited the second loaf as well.) If not, meaning that he did not equate the second loaf to another loaf that had been prohibited, but rather said, "Isar this (second) loaf upon me" this is not a valid term for an oath, and he is therefore exempt if he transgresses this oath.

Opinion #3: Alternatively, the Beraisa means as follows. "If you say that prohibiting using an oath," means that he prohibited it using a term of an oath and eating by saying, "It is upon me not to eat this (second loaf) like this (first loaf)." "If he did not," means that he did not use the term of eating, but rather said, "It is upon me that this should be like this" he is exempt.

Opinion #4: It is also possible that "Isur Isar" refers to a third prohibition, meaning that he prohibited a third loaf based on the second loaf. "If you will say prohibiting using an oath" means that the second loaf can be used to prohibit like stating an oath, just like the first loaf, he is also liable if he transgresses his oath regarding the third loaf. If not, he is exempt.

However, it is obvious to him that the law regarding the second loaf is exactly like that of the first loaf, and that he must bring a Korban for transgressing the oath. Rava argues, and says that even for the second loaf he is exempt.

Question #1: However, this is difficult. The Tana still has a doubt regarding the third loaf (see (d) above).

Question #2: Additionally, the fact that the text is "And he is liable" [with a Vav] does not sit well (see (f) above).

Explanation: If it would say, "Shevuah" I would explain that this "Mivta" she forbade on herself using a term of an oath. However, now we realize that the explanation must be, "How did she forbid herself? She did so using the term "Mivta."

Question: Doesn't it also say, "And she forbid an Isar in her father's house when she was a Na'arah?" (In the same way that the Pasuk above indicates "Mivta" is a term of an oath, this Pasuk indicates that "Issar" is a term of an oath! Why, then, is Mivta considered an oath while Isar is not?)

Answer: Being that the Pasuk did not say, "Or" it is possible that it is referring to Nedarim (not Shevuos) mentioned at the beginning of this Pasuk.

Observation #1: The Tana was not careful to say exactly what he meant. Such an oath would not be valid, as saying "I will not eat" is making an oath on something intangible, which is invalid.

This is like saying, "Konam that I will not sleep" which is invalid. The only way something similar is valid is if he says, "Konam my eyes from sleep" as stated in Nedarim (15a). Here, too, he must say, "Konam eating meat from upon me" (as he is forbidding the meat).

Observation #2: However, perhaps it is possible to differentiate that he is considered to have said nothing regarding sleep because sleep is something that is intangible. (However, he can forbid himself from something that is tangible without forbidding that thing directly, as in the case of our Gemara.)

Question: Why does Shmuel explain "Isar" as a case where a person is using a Neder to make something else forbidden? The Isar of the Pasuk discussed by Abaye is where a person is making something forbidden through a Shevuah!

Answer: It is possible to answer that we derive the concept of using a Neder to make something else (i.e. a second loaf, see TOSFOS DH ISAR above) forbidden from the fact that we do so regarding Shevuos. Shmuel therefore has no problem establishing the Beraisa as discussing Nedarim, as it is normal for people to make a Neder to refrain from eating meat and drinking wine on the day that the see Yerushalayim in its status of destruction. They do not usually forbid themselves from these things by making a Shevuah.

Implied Question: This question is asked despite the fact that Rava admits that one can make something else forbidden through something forbidden by a Neder. Rava clearly admits this, as this is a Mishnah in Nazir (20b). The Mishnah says that if someone says, "I am a Nazir" and his friend hears and says, "And I am" that he indeed has become a Nazir. Additionally, regarding Nedarim, Rava says that the term, "b'Korban" can create a Neder.

Answer: Even so, the Gemara asks its question according to Rava regarding his explanation that the Isar of the Pasuk makes things forbidden. Rava explains that he is not referring to the Isar of the Pasuk. Rava's answer is that he is not discussing the Isar of the Pasuk.

Text #1: Rashi explains that we do not have the text, "Being that this is forbidden according to Rabbinic law, if he makes a Neder the prohibition of Bal Yachel applies."

Question: Even if it was forbidden according to Torah law, we say later (25a) that Nedarim are valid regarding a Mitzvah just as they are valid regarding something that is mundane.

Text #2: However, Rabeinu Yitzchak understands that this is the correct text.

Even though the Neder would be valid even if this were something which was forbidden according to the Torah, something that was forbidden through a Neder based on this item is not deemed as such. The reason for this is that even if he would not have made the Neder, it still would be prohibited according to Torah law.

Additionally, the fact that Nedarim are valid regarding Mitzvos is only regarding transgressing Mitzvos, as stated in Nedarim (16a). The Gemara says, "What is an example of this? If a person says, "Konam that I will not take a Lulav" or "That I will not put on Tefilin." The Gemara there concludes that this is derived from the Pasuk, "When he will make a Neder to Hash-m" implying that Nedarim are even valid regarding matters of Heaven.

However, if he made a Neder to fulfill a Mitzvah, for example by saying, "Konam that I will not eat on Yom Kippur" or "That I will not eat Neveilos or Treifos" this Neder is invalid. This is because a prohibition cannot become valid when there is already such a transgression in place.

This is why the reasoning that the prohibition is only Rabbinic was stated by the Gemara.

Observation: However, according to Rebbi Yehudah ben Beseirah who holds later (27a) that someone who swears to fulfill a Mitzvah is liable, certainly Nedarim that are effective to negate fulfilling a Mitzvah are effective to uphold a Mitzvah.

Implied Question: One also transgresses Bal Yachel if he transgresses a Shevuah. This is as the Pasuk states, "Or he will swear...And he should not make his word mundane." In Nedarim (16b), the Beraisa explicitly states that one transgresses Bal Yachel when transgressing a Shevuah. (Why, then, is our Gemara saying specifically regarding Konamos that one transgresses Bal Yachel?)

Answer: The Gemara here is saying that one only transgresses Bal Yachel when transgressing Konamos.

Opinion #1: This implies that Kidush is a Torah law. This is also explicitly implied in Berachos (20b).

Question: This is difficult. In Nazir (4a), the Gemara says that we derive from "Yayin v'Sheichar Yazir" that a Nazir is forbidden from drinking wine of Mitzvah just like he is forbidden from drinking wine that is for mundane purposes. The Gemara asks, what wine are we discussing? It must be Kidush and Havdalah. However, he is already sworn from Har Sinai!

Opinion #2: Rabeinu Tam explains that the Gemara is saying this in a manner of a question. Is he really sworn from Har Sinai to drink this wine, that we require a Pasuk to exclude a Nazir from being able to drink it?! This implies that these Mitzvos are only mid'Rabbanan.

One cannot explain that the Gemara merely means to make a statement (without asking this as a question). On the contrary, if he is indeed sworn from Har Sinai to drink this wine, it is understood why the Torah must forbid it.

The Gemara indeed answers this elsewhere. It says that Rava stated that if a person vows that he will drink wine, and then proclaims himself to be a Nazir, we require a Pasuk to say that the Nazirus should be valid as he is already sworn from Har Sinai to drink wine.

Answer: It is possible to answer that Kidush is certainly according to Torah law. However, having to make Kidush on wine is only according to Rabbinic law.

Implied Question: The Gemara in Pesachim (106a) derives from the Pasuk, "Zachor Es Yom ha'Shabbos" that one must remember Shabbos over wine. (Doesn't this show that the Gemara holds making Kidush over wine is a Torah law?)

Answer #1: This is only an Asmachata (and not a real Derashah, and therefore only a Rabbinic law).

Answer #2: Alternatively, even if it is a real Derashah, the fact that a person making Kidush must taste from the Kidush is only a Rabbinic law.

Obsservation: We cannot say the opposite is true, as we compare in a stringent manner, as stated in Yevamos (8b).

Implied Question: In Kidushin (35b), we derive from the comparison between "Lo Sakifu Pe'as Rosh'chem" and "v'Lo Saschis Es Pe'as Zekanecha" that anyone who is commanded in not destroying their Peyos is not commanded in shaving around the head. Being that women are not commanded in the former prohibition etc. (they are not commanded in the latter prohibition as well). This is a teaching that is lenient! (Why are we comparing in a lenient manner?)

Answer: This is because it is impossible to derive in a stringent manner, as women do not have a beard.

Similarly, the Beraisa says in Erchin (3b),"Everyone is obligated to wear Tzitzis, Kohanim, Leviyim, and Yisraelim etc." The Gemara concludes that the Beraisa had to say Kohanim, being that one would think that if Kohanim are allowed to wear Kilayim (when they are wearing the Bigdei Kehunah), they should not be obligated in Tzitzis! The reason we would think to compare Kilayim to Tzitzis in a lenient fashion is because we cannot compare them in a stringent fashion.

Question: However, in Pesachim (43b) there is an apparent difficulty. The Gemara there implies that if not for the fact that women were specifically included in the prohibition against eating Chametz, we would derive through a lenient comparison that whoever is not commanded in eating Matzah is not commanded not to eat Chametz.

Answer #1: It is possible to answer that there we could have derived a Gezeirah Shaveh of "Chamishah Asar" from Sukos, and women are exempt from sitting in Sukos, as derived in Sukah (28a) from the Pasuk "ha'Ezrach."

Answer #2: Alternatively, there is a logical reason to derive that the Pasuk should be compared from the end of the Pasuk to the beginning of the Pasuk.

Question #1: However, this is difficult according to the opinion in Menachos (43a) that Tzitzis is a "Mitzvas Asei she'ha'Zeman Gerama" from which women are exempt. If so, we should allow women to wear Kilayim by saying that anyone who is not commanded to wear Tzitzis is not prohibited from wearing Kilayim! We should derive the comparison in this fashion, as this is deriving from the latter Pasuk to the former Pasuk.

If you will say this is correct (and women are exempt), the Gemara in Beitzah (14b) is difficult. When the Gemara discusses sending clothes whether they are sown or not yet sown, and the Gemara asks that Kilayim are not fit for anything, why doesn't the Gemara say that the Mishnah is according to the opinion that women are exempt from Tzitzis? They are fit for women!

Question #2: Additionally, according to the opinion that we always compare stringently, women should be obligated in Tzitzis according to everyone! (We know, however, that there are many opinions that do not hold a woman is obligated in the Mitzvah of Tzitzis.)