Explanation: This is needed [to teach that copper acquires silver]. Even though in a place where Perutos (copper coins) are accepted, they are accepted more than silver, [copper coins] are the commodity, because there are places where they are not accepted, like it says in the Gemara (44b).

Question #1: Why do we need to teach that bad coins that were disqualified are called a commodity?

Copper coins, which are accepted more, are the commodity. All the more so bad coins that were disqualified [are commodity]!

Question #2: The Gemara (46b) establishes "all Metaltelim acquire each other" to discuss [Chalipin with bad] coins, whether they were disqualified in the whole kingdom, or one province ceased to accept them. (Currency is invalid for Chalipin);

All the more so disqualified coins are called commodity with respect to silver!

Answer: "Bad coins" means that they are accepted a little.

Implied question: Why must it teach Asimon (a blank coin without a mintage)?

Answer #1: According to Rashi, who says that an Asimon is made like coins accepted in the city, and it is lacking only a Tzurah (form, i.e. mintage), this teaches that even so, it is considered commodity;

Even though it lacks only a small matter, for it is a small matter to put a Tzurah on many of them [even so, they are commodity].

Answer #2: According to R. Tam, who says that an Asimon has a Tzurah, but it is not accepted, we must say that it is accepted with difficulty, but with less difficulty than bad coins are.

Implied question: Why do we need "Metaltelim acquire coins"?

Answer: This teaches that they acquire even coins like bad coins or an Asimon, which are called commodity with respect to silver, and with respect to Metaltelim they are called currency.

Explanation #1 (Rashi): [An Asimon] does not have a Tzurah at all.

Question (R. Tam): In Shabbos (65a) they said that one may go out (in Reshus ha'Rabim on Shabbos) with a Sela (coin) on a wound [on his foot];

Citation (65a): If [it helps the wound] due to the Tzurah, he should make a Pulsa (this will be explained) for it;

Inference: Pulsa has a Tzurah. The Gemara below (46b) explains that Asimon is a Pulsa!

Answer: Rashi can say that anything that is not like it should be is called Asimon. Either it has no Tzurah, or it has a Tzurah that is not important.

Question: What is the difference between an Asimon without a Tzurah, and coins given for a sign in the bathhouse?

We say in the Gemara (there) that all agree [that we can not redeem Ma'aser Sheni on such coins. Even] R. Dosa, who said that we can redeem Ma'aser Sheni on an Asimon, agrees that we cannot not redeem on such coins!

Answer: We must say that Asimon is a coin made with the width, thickness and weight of a coin accepted in the city, and it is a small matter to put a Tzurah on many of them. Therefore [R. Dosa holds that] we can redeem on an Asimon.

Explanation #2 (R. Tam): An Asimon has a Tzurah, but sellers do not accept it.

Question: In the Gemara, it says that R. Dosa, who says that we redeem on an Asimon, and R. Yishmael, taught the same matter.

Citation (47b - Beraisa - R. Yishmael): "V'Tzarta ha'Kesef [b'Yadecha]" includes anything that may be Nitzrar (wrapped) in the hand;

Citation (cont. - R. Akiva): This includes something with a Tzurah.

Inference: R. Yishmael does not require a Tzurah, and [according to R. Tam] an Asimon has a Tzurah.

Summation of question: If so, they (R. Dosa and R. Yishmael) did not teach the same matter!

Answer: "To include anything that may be wrapped in the hand" [means] even if it is not accepted, but it has some (albeit inferior) Tzurah;

R. Akiva requires an important Tzurah, that it is accepted.

Observation: He does not require that it is totally accepted, since we need to include [that one may redeem on it].

According to Rashi [who says that it has no Tzurah, or its Tzurah is not important] it is fine that we need an inclusion.

Implied question: Why did Rav ask R. Chiya? This is a Mishnah below (75a)!

Answer: Perhaps the Halachah follows Hillel. [Amora'im] argue there about whether the Halachah follows Hillel.

Question #1: Here it connotes that Isar is considered currency more than a Perutah, since we require a Perutah to be an eighth of an Isar;

In Kidushin (12a), it says "this [discusses] when Isarim are expensive, and this [discusses] when they are cheap";

The Beraisa that says that a Perutah is an eighth of an Isar, it discusses when Isarim are cheap, and there are 32 [Isarim] in a Zuz. (A Perutah is an sixth of an Isar when Isarim are expensive, and there are 24 Isarim in a Zuz. We always attribute change of value to the commodity, and not to the currency!)

Question #2: What was the question below "does the Tana measure with something that can become expensive or cheap?!" Here the Tana measures with an Isar, which can become expensive or cheap, like it says in Kidushin!

Question #3: Since he measures [the Isar] based on silver Dinarim (it is a 24th of a silver Dinar), he must hold that the Isur does not have a fixed value!

Answer: It means "a Perutah is an eighth of an Isar. Which Isar do we discuss? An Isar that is a 24th of a silver Dinar, and there are 25 silver Dinarim in a gold Dinar;

Now, everything is measured based on a gold Dinar. Therefore, we ask from this (to show that gold cannot be a commodity);

However, we do not measure anything based on the Isar and silver Dinar [themselves. We measure with them on condition that they are a 600th and a 25th of a gold Dinar, respectively. It turns out we measure only based on a gold Dinar.]

Implied question: We could have said that all of these are relevant to Kidushin of a woman! (We must teach all of them in order to gauge a Perutah, that it is a 4800th of a gold Dinar.)

Answer: Rather, it mentions a [different] Nafka Minah (consequence of the Shi'ur) for each.

Support: Likewise, we could have said that all of them are relevant to business!

Observation: We could have said that this is relevant for the five matters for which the Shi'ur is a Perutah, in our Mishnah below (55a). We mentioned only one of them.

Explanation #1 (Rashi): If one sold to him a Dinar for more than 24 Isarim, the buyer was overcharged, and if [the overcharge] was a sixth, he returns it.

Question: Sometimes Isarim are cheap, like we say in Kidushin (12a)!

Explanation #2: Rather, if he sold to him an item worth 24 Isarim when there are 24 Isarim in a Dinar, and afterwards [Isarim] became cheap and there are 32 in a Dinar, [the buyer] cannot exempt himself through paying 24 Isarim, and say "the Dinar became expensive, and Isarim remained intact";

Rather, he gives to him a silver Dinar or 32 Isarim.

Question (R. Tam): How can it be that in their days, gold was so expensive, that a gold Dinar was worth 25 silver Dinarim, and nowadays a gold Zakuk (a coin of a certain weight) is not worth more than 12 silver Zekukim?

Answer (R. Tam): A gold Dinar weighed twice as much as a silver Dinar, because gold is denser than silver. Also, the gold Dinar was thicker Dinar than the silver Dinar;

Source: It says in Chulin (55b) "if remained like the thickness of a gold Dinar", and in Eruvin (19a) and Chagigah (27a) it says "the thickness of the [gold] Mizbe'ach was only like that of a gold Dinar";

Inference: The thickness of a gold Dinar is unlike that of a silver Dinar.

Due to its thickness and density, it was worth 25 silver Dinarim. It is not proper to elaborate more here.

Note: Gold is about 1.84 times as dense as silver. If a gold Dinar was about a 12th thicker, it weighed twice as much. Nowadays, silver is worth only about a 75th as much as gold. The discovery of America, and its vast amounts of silver, cheapened it.

Implied question: In Bava Kama (97b) regarding redeem [Ma'aser Sheni] on coins of Bavel in Bavel, it asks "if the kingdoms are adamant (that people not take their coins outside their countries), how will one take them to Yerushalayim [to buy food and drink there?", and answers that] he buys with them an animal [and takes the animal to Yerushalayim].

Inference: One may redeem currency on Peros (food)!

Answer: There is different, for the Peros are [too] heavy to take [to Yerushalayim], and one cannot buy coins of Yerushalayim [in Bavel], because the kingdoms are adamant, so there is no solution other than buying an animal.