Maaser Sheni, Chapter Two, Mishnah 9. In the previous mishnah we dealt with transferring maaser sheni money from outside Yerushalayim: a person gathers copper coins and transfers their sanctity onto a silver coin so that he can bring it up to Yerushalayim, and the question was whether he must leave some of the copper coins in his possession or whether he may transfer all of them onto the silver coin. Our mishnah deals with the reverse case: after a person has arrived in Yerushalayim holding the silver coins he brought up, and he wishes to transfer their sanctity onto copper coins so that he will have small change to spend - must he convert all of the silver coins into copper, or only part of them?
The text of the mishnah:
"Haporet sela shel maaser sheni biYerushalayim" - one who wishes to break down the sela of maaser sheni that he brought up to Yerushalayim and exchange it for small coins. On this question there are many differing views:
Beis Shammai say "kol hasela maos" - a person may convert all the silver coins in his possession into small coins, even though he does not need them all at once. Some understand that according to Beis Shammai this is even the preferred course, since every visit to the money changer involves a fee, and in this way he pays the fee only once rather than each time anew.
And Beis Hillel say "shekel kesef v'shekel maos" - he should break down only half. The reason: he may not need all the small change, and he will be forced to set the remainder aside until the next festival, until his next trip up to Yerushalayim; and copper coins are liable to spoil and develop verdigris. And if he then wishes to convert them back into silver coins, he will incur an additional fee. Therefore Beis Hillel said: he should do half and half.
Additional opinions cited in the mishnah:
"Hadanin lifnei chachamim" - the students who would sit before the Sages and debate the halachah in their presence: Shimon ben Azzai, Shimon ben Zoma, Chanan HaMitzri and Chananya ben Chachinai, the four of them. They too hold like Beis Hillel that one may not convert the entire sum, except that they did not set the measure at half: of each sela, which is made up of four dinars, they said "bishloshah dinarim kesef uv'dinar maos" - three of the four remain in the status of silver, and only one of the four dinars is converted into copper coins, for limited spending.
Rabbi Akiva - proposes a further formula: three of the four dinars in the sela remain silver, and so do three quarters of the fourth dinar; only a quarter of the fourth dinar - which is one sixteenth of the sela - is converted into small change, into copper coins. Some understand his words slightly differently: that the fourth dinar is divided in two, in which case an eighth of the sela is converted into copper.
Rabbi Tarfon - says that from that fourth dinar one should take "arbaah asparim" of silver. What is an 'aspar'? On this there is a difference of opinion:
Some understand that each dinar is made up of five asparim. According to this understanding, of the fourth dinar four asparim out of five remain in the status of silver, and only the fifth - a fifth of a dinar - is converted into copper perutos, which is one twentieth of the sela.
Others understand that an 'aspar' is what is called a 'maah', which is a sixth of a dinar. According to this, four out of six remain, which is two thirds of the dinar, in the status of silver, and only a third of the dinar is converted into perutos - which is one twelfth of the sela.
The opinion of Shammai himself:
The last opinion in the mishnah is that of Shammai himself - not Beis Shammai, but Shammai. He proposes an entirely different plan: one should not convert the sela into perutos at all. Instead, a person should find a particular store, deposit there all the maaser sheni money in his possession, and eat against it while keeping an account with the storekeeper of exactly how much he has spent - and in this way there is no need to convert any part of the sela into small change.
The reason for his view: Shammai was concerned that a person might forget and use the copper coins for ordinary purposes. He therefore said that it is preferable to leave the sela in the store in the storekeeper's hands, and to receive food on the basis of the sela deposited with him.
In summary: our mishnah deals with breaking down a sela of maaser sheni in Yerushalayim, and several measures were stated regarding it: Beis Shammai - the entire sela into small change; Beis Hillel - half silver and half small change; those who debated before the Sages - three dinars silver and one dinar small change; Rabbi Akiva - three dinars and three quarters of the fourth dinar in silver (and according to another view, half of the fourth dinar); Rabbi Tarfon - four asparim of silver from the fourth dinar, according to the two understandings of the measure of an 'aspar'; and Shammai himself - that one should not break it down at all, but rather deposit the sela with the storekeeper and eat against it by account.