(Abaye): Sometimes, Eifa's answer is correct, for example in Rabah's case.

Version #1 -Rashi - (Rabah): If one said 'I swear that I will not eat figs and grapes (on the same day), I swear that I will not eat figs', and he (forgot the oaths and) ate figs, (realized his mistake,) separated a Korban (for the latter oath, forgot the first oath and) ate grapes, he is not liable for the first oath. Since separating the Korban disassociates eating the figs from eating the grapes, we consider that he violated only half of the first oath, so he does not bring a Korban for it.

Version #2 - Tosfos - (Rabah): If one said 'I swear that I will not eat figs, I swear that I will not eat figs and grapes (together; even though he already swore not to eat figs, since he creates a new Isur on grapes, the oath takes effect)', and he (forgot the oaths and) ate figs, (realized his mistake,) separated a Korban and (forgot his oath and) ate grapes, he is not liable for the second oath. Since separating the Korban disassociates eating the figs from eating the grapes, we consider that he violated only half of the second oath, he does not bring a Korban for it. (end of Version #2)

Here also, if he swore 'I will not eat ten figs, I will not eat nine figs', he ate nine, separated a Korban and ate a tenth, separating the Korban disassociates the nine figs from the tenth, so he is not liable for the first oath.

(Mishnah): The following are vain oaths:

An oath that contradicts what people know to be true, e.g. 'this pillar (which all can see is stone) is gold', or 'this is a woman (all can see it is a man)', or vice-versa;

He swore about something impossible, e.g. 'if I did not see a camel fly in the air, or a snake like the beam of an olivepress';

Witnesses were asked to testify, and they swore that they will not;

One swore not to fulfill a Mitzvah, e.g. not to dwell in a Sukah, take a Lulav or don Tefilin;

These are vain oaths. One who b'Mezid swears in vain is lashed. If he did so b'Shogeg, he is exempt.

If one said 'I swear that I will eat this loaf, I swear that I will not eat it', the first is Shevu'as Bituy, and the latter is a vain oath;

If he eats the loaf, he transgressed swearing in vain. If he does not eat it, he transgressed (even) Bituy.

(Gemara - Ula): Something is considered known to people if three people know it.

(Mishnah): He swore about something impossible, e.g.'if I did not see a camel fly.'

Question: 'I saw a camel fly' is a vain oath. However, he did not say that, rather, 'if I did not see a camel fly.' This is not an oath!

Answer #1 (Abaye): Indeed, the Mishnah should say 'I saw a camel fly.'

Answer #2 (Rava): This is part of the previous case, he swore (to do something impossible, e.g.) 'all food is forbidden to me (through a Shevu'ah) if I did not see a camel fly.'

Question (Ravina): Perhaps the man saw a huge bird, nicknamed it 'camel' and swore truthfully based on his Da'as (intent of his words)!

Answer: We judge oaths (objectively) based on the words he said, and not based on his personal intent.

Question #1 (Beraisa): When Beis Din administers an oath, we tell the one who must swear 'you do not swear based on your own Da'as, rather based on the Da'as (understanding) of Hash-m and Beis Din.'

Suggestion: If Beis Din did not say this, he could swear based on his Da'as, e.g. he could nickname some wood chips 'money', and swear 'I gave the money to Ploni'!

Answer: No. (Really, we judge oaths objectively based on his words, and not based on his Da'as);

We are concerned for cases like what occurred in front of Rava. (A man hid money in a stick, asked his creditor to hold the stick, and swore 'I gave you your money'! This was literally true, but it was unlike Beis Din's understanding.)

Question #2 (Beraisa): When Moshe forced Bnei Yisrael to swear, he said 'I do not make you swear based on your Da'as, rather based on Hash-m's Da'as and mine.'

Suggestion: He could not simply ask them to swear to fulfill what Eloka (G-d) said, lest they swear based on their own intention, e.g. they would call an idol 'Elo'ah' and swear by it.

Answer: No, that would be based on the objective meaning of the words. Idols are called Elo'ah - "Elohei Kesef."

Question: Why didn't he make them swear to observe the Torah?

Answer: They could say 'we swore to observe only one Torah (written or oral).

Likewise, had he made them swear to observe two Toros, they could say 'we swore only to observe the Toros (laws of) Chatas and Olah;

Had he made them swear to observe the entire Torah, this could be construed to mean idolatry, which is equivalent to the entire Torah;

Had he made them swear to observe Mitzvah, this would only mean one Mitzvah. 'Mitzvos' would mean only two Mitzvos;

Had he made them swear to observe all the Mitzvos, this could be construed to mean Tzitzis, which is equivalent to the entire Torah;

Question: Why didn't he make them swear to observe 613 Mitzvos?

Counter-question: Why did he have to make them swear based on Hash-m's and Moshe's Da'as? It would have sufficed to swear based on Moshe's Da'as'!

Answer to both questions: This is in order that the oath (will be based on the Da'as of many (others), so it) cannot be annulled.

(Mishnah): ...'If I did not see a snake like the beam of an olivepress'

Question: A bigger snake was seen in the days of Shevor Malka. It consumed 13 stables (or bundles) of hay.

Answer (Shmuel): He means, it was Taruf (Rashi - grooved) like the beam of an olivepress.

Question: All snakes are like that!

Answer: He means, its back was Taruf.

(Mishnah): If one said 'I swear that I will eat this loaf, I swear that I will not eat it... '(if he does not eat it, he transgressed Bituy).

Question: Why is he liable only for Bituy, and not for (the latter,) a vain oath?

Answer (R. Yirmeyah): Indeed, the Mishnah means, he transgressed even Bituy.

(Mishnah): Oaths of Bituy apply to men and women, (whether he swore to help) relatives and strangers, people qualified and unqualified to testify, in and outside of Beis Din, when he swears himself;

He is lashed if he transgressed b'Mezid, and brings an Oleh v'Yored if he was Shogeg.

Vain oaths apply to men and women, (whether he swore about) relatives and strangers, people qualified and unqualified to testify, in and outside of Beis Din, when he swears himself;

He is lashed if he transgressed b'Mezid. If he was Shogeg, he is exempt.

Another person can put either oath on him. If Reuven said 'I did not eat (or don Tefilin) today', and Shimon said 'I impose this on you through a Shevu'ah', and Reuven answered 'Amen', he is liable.

(Gemara - Shmuel): One who answers 'Amen' to an oath is like one who said the oath himself - "v'Amrah ha'Ishah Amen Amen" (if the Sotah is guilty, she will die for this oath).

Support #1 (Rav Papa): Shmuel must be correct. This is the only way to resolve a contradiction between a Mishnah and Beraisa;

(Mishnah - R. Meir): Shevu'as ha'Edus (the oath of not knowing testimony) applies only to men, only to strangers, only to Kosher witnesses, only to people proper to testify (this excludes kings), in or outside of Beis Din;

When he swears himself, he is liable anywhere. If the oath is imposed on him, he is liable only if he denies in Beis Din.

Contradiction (Beraisa - R. Meir): Shevu'as ha'Edus is when Reuven asked witnesses to testify for him; and they said 'we swear that we do not know testimony for you';

Or:, they said 'we do not know testimony for you', and Reuven said 'I impose this on you through an oath', and they answered 'Amen', whether in or outside of Beis Din, whether they swore themselves or the oath was imposed on them, they are liable if they deny in Beis Din.

Resolution: When they answer 'Amen', they are liable even outside of Beis Din. If they (accepted the oath but) did not say 'Amen', they are liable only in Beis Din.

Support #2 (Ravina): We can resolve a contradiction in our Mishnah only like Shmuel.

(Mishnah): Oaths of Bituy apply... when he swears himself;

Inference: It does not apply when the oath was imposed on him.

Contradiction (Seifa): Another person can put either oath on him.

Resolution: When they answer 'Amen', they are liable even outside of Beis Din. If they (accepted the oath but) did not say 'Amen', they are liable only in Beis Din.

Question: What is Shmuel's Chidush? The Mishnah teaches this?

Answer: Shmuel teaches that the Mishnah teaches this law.