(Gemara - Mishnah #1): If a vow forbids Shimon to benefit from Reuven, Reuven may give the half-Shekel for Shimon, he may pay Shimon's debt, and he may return an object Shimon lost;

In a place where one receives money for returning Aveidos, this amount is given to Hekdesh.

Question: Granted, he may give his half-Shekel, for this is a Mitzvah;

(Mishnah): When half-Shekalim are taken (from the chamber) for buying Korbanos, they have in mind people whose half-Shekalim were lost, collected, or will be collected. (Rashi - in any case Shimon has a share in the Korbanos, so Reuven does not benefit him. Tosfos - Reuven may give 'compensation' on behalf of Shimon only when Shimon already gave and his Shekel was lost and Shimon need not give again.)

We also understand why he returns Shimon's Aveidah. This is also a Mitzvah;

Why may he pay Shimon's debt? This saves Shimon money!

Answer #1 (R. Oshaya): Mishnah #1 is like Chanan, who says that one who feeds his friend's wife threw away his money. (Likewise, one need not repay one who paid his debt. Rashi - Reuven did not give anything to Shimon. Tosfos - he only causes benefit to him; the vow does not forbid this.)

Answer #2 (Rava): Mishnah #1 is even like Chachamim. The case is, the loan was on condition that the lender cannot demand payment.

Question: Granted, Rava did not answer like R. Oshaya, for Rava prefers to establish the Mishnah even like Chachamim;

Why didn't R. Oshaya answer like Rava?

Version #1 - Answer: Granted, repaying such a loan is not like giving him money, but he spares him shame. (We follow the Bach's text.)

Version #2 - Answer: In Rava's case, he benefits him. He spares him shame. (Rav Ransberg - according to this version, sparing him shame is considered proper benefit.)

(Mishnah): Admon said seven laws (they are in the coming Mishnayos). The first is the following:

If a man died leaving sons and daughters, if the estate is big (enough to feed all the children for 12 months), the sons inherit and the daughters are fed. If the estate is small, (Chachamim say that) the daughters are fed and the sons beg for their food;

Admon: Why should a male lose?!

R. Gamliel: I agree with Admon.

(Gemara) Question: What is Admon's astonishment?

Answer #1 (Abaye): Why should a male lose? He is fitting to learn Torah!

Objection (Rava): Does only one who engages in Torah inherit?!

Answer #2 (Rava): Rather, a male inherits when there is much property. Why should he lose when there is little property?!

(Mishnah - Admon): If Reuven claims that Shimon owes him barrels of oil and Shimon admits that he owes barrels, since he admits to part of the claim, he must swear;

Chachamim say, the admission is not from the same class as the claim (so he need not swear).

R. Gamliel: I agree with Admon.

(Gemara): From Chachamim we learn that if Reuven claims wheat and barley and Shimon agrees that he owes barley, he need not swear that he does not owe wheat.

Question: This refutes Rav Nachman!

(Rav Nachman): If Reuven claims wheat and barley and Shimon admits to one of them, he must swear.

Answer #1 (Rav Yehudah): In our Mishnah he claimed a measure of oil, not barrels.

Rejection: If so, why do Chachamim obligate him to swear?

Answer #2 (Rava): All agree that if Reuven said 'I own the volume of 10 barrels of oil in your pit', he only claims oil, not barrels;

If he said 'I have 10 barrels full of oil by you', all agree that he claims oil and barrels;

They argue about when he said 'I have 10 barrels of oil by you'.

Admon says, these words include the barrels. Chachamim say that they do not.

Inference: If Chachamim would agree that these words include the barrels, they would agree that he must swear.

Question: This refutes R. Chiya bar Aba!

(R. Chiya bar Aba): If Reuven claims wheat and barley, and Shimon admits to one of them, he need not swear.

Answer #1 (Rav Simi bar Ashi): Claiming barrels and oil is like claiming a pomegranate and its peel (i.e. they are like one class).

Rejection (Ravina): A pomegranate cannot last at all without its peel, but oil can last without barrels!

Answer #2 (Ravina): The case is, he said 'I have 10 barrels of oil by you.' Shimon denied having any of his oil, but admitted to having five barrels;

Admon says, these words (10 barrels of oil) include the barrels. Since Shimon must swear about the barrels, he must also swear about the oil through Gilgul (once one must swear about one matter, his opponent can force him to include other matters in the oath);

Chachamim say that these words do not include the barrels. Shimon totally denied the claim, so he need not swear.