CAN COINS BE ACQUIRED THROUGH CHALIPIN?
Question (Mishnah): If Reuven was in a granary, and he did not have coins (and wanted to evade the additional fifth that one who redeems his own Ma'aser Sheni must add), he tells Shimon 'my Ma'aser is given to you for a gift.' Reuven then redeems the Ma'aser on coins in his own house (and trusts that Shimon will return the Ma'aser to him).
Inference: If Reuven had coins, it is better to give them to Shimon, and let Shimon redeem the Ma'aser (this is a less overt ruse to evade the fifth), for it is not Shimon's Ma'aser.
Summation of question: If coins can be acquired through Chalipin, Reuven should give the coins in his house to Shimon through Chalipin!
Answer: The case is, he does not have a Kli with which to do Chalipin.
Question: Reuven should give the coins to Shimon Agav (along with) land!
Answer: The case is, Reuven does not have land.
Question: It says that he was standing in a granary. That is land!
Answer: The case is, it belongs to someone else.
Rejection: This is unacceptable, to say that the Mishnah gives counsel for a man without clothes (who does not have anything with which to make Kinyan Sudar)!
Rather, coins cannot be acquired through Chalipin.
The following shows that Rav Papa himself retracted.
Rav Papa had 12,000 Dinarim in Bei Chuzai. He gave them to Rav Shmuel bar Acha, Agav the corner of his house, in order that the Shomer would give them to Rav Shmuel (to return to Rav Papa). When Rav Shmuel was returning with the money, he went out to Tavech to meet him (Rav Papa gave them Agav, and not through Chalipin, for he retracted from saying that Chalipin can acquire coins. Maharam Shif - presumably, he was Makneh the corner of the house through Chalipin. If he held that Chalipin acquires coins, there was no need for Agav. One may ask, he went to Tavech to meet him out of Simchah, for he had worried lest the Shomer in Bei Chuzai hold that Agav requires Tziburim (the Metaltelim must be on the land given; this was not obvious - see Kidushin 26b-27a), and refuse to give them to Rav Shmuel. Perhaps Rav Papa did not retract. He did not use Chalipin, lest the Shomer hold that Chalipin does not acquire coins! However, if so he should have done both Kinyanim, lest the Shomer hold that only one of them works. We must say that he did not use Chalipin for he retracted, and did not want people to think that he still holds that it acquires coins - PF.)
(Ula, Rav Asi, Rabah bar bar Chanah): Coins cannot be acquired through Chalipin.
Question (R. Aba - Beraisa): If Reuven's workers were demanding payment from Reuven in the market, and he told a moneychanger 'give me a Dinar's worth of coins (to pay them), I will give you the value of a Dinar and an (extra) Trisis' this is permitted only if Reuven has the coins in his house.
If coins cannot be acquired through Chalipin, (even if he has coins in his house) this is a loan with Ribis!
Ula was unable to answer.
Answer #1 (R. Aba): Perhaps all the coins mentioned are blank, therefore they are considered commodities, not coins.
Support: 'The value of a Dinar and a Trisis' suggests that they were not actual coins.
Answer #2 (Rav Ashi): True, the Beraisa discusses blanks, but we need not say that he acquired them through Chalipin;
Since he had at home the same thing he borrowed, it is permitted. (Since he will return it very soon, this is unlike Ribis, which is payment for borrowing for a period of time.)
CAN A COIN BE USED TO DO CHALIPIN?
Question (Mishnah): Whatever is (normally) made (given to be) payment for other things, once Reuven acquires it, Shimon is obligated to give what it was traded for.
Suggestion: The Mishnah discusses money, and it does Chalipin!
Answer (Rav Yehudah): No, it means anything that must be made into money (i.e. appraised). It refers to Metaltelim.
Support (Reisha): How is this? If he exchanged an ox for a cow, or a donkey for an ox...
Question: The one who made the above suggestion understood that the Mishnah discusses money. How did he understand this?
Answer: The Mishnah (is abbreviated, it) means: Peros (i.e. Metaltelim that are not Kelim) also do Chalipin. How is this? If he exchanged an ox for a cow, or a donkey for an ox...
Question: Granted, Rav Sheshes can answer like this, for he says that Peros do Chalipin;
How can we answer for Rav Nachman, who says that only Kelim can do Chalipin?
Answer: The Mishnah (is abbreviated, it) means: There is a form of money that acquires like Chalipin (i.e. without moving the commodity). How is this? If he was owed money for an ox and exchanged (the debt) for a cow, or money owed for a donkey for an ox...
Question: Why does this work?
Answer: Rav Nachman holds like R. Yochanan, that mid'Oraisa, (paying) money acquires Metaltelim;
Chachamim enacted that Meshichah acquires (but money does not), lest someone sell something in his house (without giving it over immediately), and be slothful about saving it from a fire;
Chachamim decreed only in a common case. It is not common to buy with money owed from a sale (so this still acquires, like Torah law).
Reish Lakish says that mid'Oraisa, Meshichah acquires Metaltelim, but money does not. If he rules like Rav Sheshes (that Peros do Chalipin), he can explain the Mishnah like Rav Sheshes.
Question: If Reish Lakish rules like Rav Nachman (that only Kelim do Chalipin), how can he explain the Mishnah?
Answer: We must say that Reish Lakish rules like Rav Sheshes.
(Mishnah): All Metaltelim acquire each other.
(Reish Lakish): Even a wallet full of coins acquires a wallet full of coins.
(Inference: This can only be through Chalipin. We learn that coins can be acquired through Chalipin!)
(Rejection) (Rav Acha): He refers to disqualified coins (they are commodities).
The law is the same whether they were disqualified in the whole kingdom, or one province ceased to accept them.
He needed to teach both of these;
Had he taught only when they were disqualified in the whole kingdom, one might have thought that when they are unusable only in one province, they are still considered currency, and are not acquired through Chalipin;
Had he taught only when they are unusable only in one province, one might have thought that that is because they cannot be used (there) in public or private, but when they were disqualified in the whole kingdom, they can be used in private, they are still considered currency, and are not acquired through Chalipin.