Explanation: [In every case of Chalipin, one is adamant] that it have some worth, and sometimes [he is adamant] that it be worth like the [sale] item itself, and even when it is not worth like the item corresponding to it (for which it is traded), he acquired.

Explanation: [He acquires] through the law of money. Above, it means "this money, since it is not common, it is like Chalipin."

Explanation: [Chalipin acquires] specifically through the seller's Kli, and not through the buyer's Kli, for below we learn from a verse.

If Levi holds that coins do not make Chalipin, and also Peros [do not], the reason is because [the seller] must receive Hana'ah that the buyer received something important [from the seller], similar to a shoe, and not a coin or Pri.

Question (R. Tam): Just the contrary! This verse proves that Ge'ulah is not a sale!

Answer: Rather, the text says "Lo Yiga'el" written regarding Ma'aser Behemah;

We say in Bechoros (32a) that "Lo Yiga'el" means "it will not be sold." One may not sell it alive, and not slaughtered.

Explanation (R. Tam): Ge'ulah is a sale. According to R. Yochanan, Ge'ulah is Kesef (which acquires mid'Oraisa). According to Reish Lakish, it is Meshichah;

"Temurah" is Chalipin of an even swap, which works according to everyone even with Peros;

"Le'kayem Kol Davar" include Chalipin [that is] not an even swap. One opinion holds that it is even a coin or Peros, and the other holds that it is only with a Kli.

Question: In Pesachim (32b), we say regarding "v'Nasan la'Kohen Es ha'Kodesh" that Nesinah (giving) cannot be less than Shaveh Perutah. Also here, it says "v'Nasan l'Re'ehu" (we should require a Perutah for Chalipin)!

Answer: There, it is payment for stealing Hekdesh (Terumah). Therefore, it cannot be less than a Shaveh Perutah, just like Me'ilah, which is payment;

However, here it is giving a shoe to his colleague, and not monetary payment.

Support #1: Similarly, "v'Nasan b'Yadah" regarding a Get. It is giving of a Get, and not giving money;

This is like it says in Gitin (20a) that if one wrote [a Get] on Isur Hana'ah, it is Kosher (even though he will give to her a Get worth nothing).

Support #2: Similarly, regarding giving Terumah (Chulin 137b), one blade of wheat exempts the entire stack (even though it is not Shaveh Perutah. Tosfos (Shabbos 25b DH Titen) says that one must give a Perutah's worth of Terumah, because it says "Titen". The Mishneh l'Melech explains that one may separate any amount to fix Tevel, but one fulfills the Mitzvah of giving it to a Kohen only if he gives at least Shaveh Perutah.)

Support #3: Regarding anointing (with Shemen ha'Mishchah), it says "va'Asher Yiten", and there is an opinion that [one is liable] for any amount, even though it is Me'ilah;

This is because it is written "Sichah", which connotes any amount.

The one who says that the Shi'ur is a k'Zayis holds like Rabanan [who argue with] Aba Sha'ul, and say that "Nesinah" is a k'Zayis, like a Zar who ate Terumah.

Implied question: Regarding Levonah (frankincense) we require a k'Zayis in Menachos (59b)!

Answer: This is because [the Torah] changed from the expression of Simah (putting), with which it began.

Implied question: Regarding a Sudar (scarf), it says above (7a) that [if one grabbed] three by three fingers, it is as if it was divided (yet this suffices for Kinyan Sudar)!

Answer: This is considered a specific (whole) matter.

Explanation: These are date pits. They are used to smooth parchment.

Inference: The Halachah follows Rav.

Support: We say in Gitin (39b) regarding a slave [whose master threw his hat to her] and said 'acquire it and acquire yourself [with it]';

The case came in front of Rav Nachman. He ruled that nothing happened, for this is the seller's Kelim.

Explanation: [If we would say that the Seifa explains the Reisha, that an Asimon is a coin given for a sign in the bathhouse,] the text does not have a Vov in "v'Al (and on) coins given in the bathhouse."

Question (Rivan): Why did Chachamim uproot the Kinyan of coins, which is mid'Oraisa? They should have enacted to require both coins and Meshichah [to acquire]!

Answer (Rivan): If Meshichah did not acquire by itself, the buyer (if he did Meshichah but did not pay yet) would tell the seller "your wheat burned in the attic" (he would be sloth to save it from a fire).

Explanation #1 (Rashi): The seller will toil to save it, because he can retract if it gets more expensive, and the buyer cannot retract if it gets cheaper.

Question: Did they enact Meshichah for improper people who will toil to save, so if it gets more expensive, he will retract and accept a Mi she'Para (curse)? Tzadikim never retract, even if it gets more expensive!

Answer: Surely, they enacted only due to improper people who will leave their colleagues' Peros to burn.

Explanation #2 (R. Tam): If they burned, the buyer can retract even according to R. Shimon.

Source: Below (49b), on the Mishnah in which R. Shimon says "whoever is holding the money [has the upper hand]", it brings an episode in which a man gave money for wine, and [he heard that] the house of Parzuk Rufila (a powerful official) was marrying off a child (and they would confiscate people's wine for this);

Rav Chisda said "just like Meshichah was enacted for sellers (that they can retract until Meshichah is done), also for buyers."

Inference: Rav Chisda holds like this even according to R. Shimon;

He need not even accept a Mi she'Para, since he did not say "go accept a Mi she'Para", like R. Yochanan told R. Chiya bar Yosef, who bought salt and it became more expensive.

Explanation #2 (cont.): The seller will toil to save it, lest the buyer retract, and [the buyer] will not even get a Mi she'Para;

Even due to a change in price, the buyer can retract even according to R. Shimon, like is proven below (74b);

It says "when did R. Shimon say that the seller can retract, but the buyer cannot? When there is one price, i.e. the price remained stable. If there were two prices (it changed), did he say?!"

There he admits that even the buyer can retract. If you would not say so, does he hold that Mi she'Para does not apply to a buyer?!

Implied question: In our Sugya, we say that R. Shimon does not hold like Rav Chisda [who said that Meshichah was enacted also for buyers, so they can retract]!

Answer: This is when it did not get cheaper or more expensive. According to Rabanan and Rav Chisda, both of them may retract;

According to R. Shimon, the seller can retract, because the money is in his hand, and the buyer cannot.