Bava Metzia

A denar may not be lent for a denar [to be returned].  Now, which denar is meant? Shall we say, a silver denar for a silver denar [to be repaid]: but is there any view that it does not rank as money even in relation to itself?  Hence it must obviously mean a gold denar for a gold denar. Now, with whom [does this ruling agree]? If with Beth Hillel — but they maintain that it ranks as coin! Therefore it must surely be in accordance with Beth Shammai, thus proving that it was R. Johanan who held that such redemption is not permissible! — No. In truth, I may assert that R. Johanan ruled that such redemption may be made, but a loan is different. For since the Rabbis treated it as produce in reference to buying and selling,  as we say that it is that [sc. gold] which appreciates or depreciates,  it ranks as produce in reference to loans too. This is reasonable too. For when Rabin came,  he said in R. Johanan s name: Though it was ruled that a denar may not be lent for a denar [to be repaid], yet the second tithe may be redeemed therewith. This proves it. Come and hear: If one changes  a sela''s worth of second tithe [copper] coins, Beth Shammai rule: the full sela''s worth of coins must be changed.  But Beth Hillel rule: [He may change] only a shekel's worth into silver, and retain a shekel's worth of coins.  Now, if in Beth Shammai's opinion redemption may be made with [copper] perutahs,  can there be a doubt that it may be redeemed with gold? — Copper coins are different, for where they circulate, they have greater currency. Another version puts is thus: R. Johanan and Resh Lakish [differ thereon]: One maintains that the dispute concerns changing sela's for [gold] denarii. Beth Shammai hold that 'the money' implies the first money, but not the second;  whereas Beth Hillel argue, 'the money … money' implies extension,  thus including even a second [redemption of] money. But all agree that [actual] produce may be redeemed by [gold] denarii, since it [sc. the gold denarii] is, after all still the first money. Whilst the other maintains: The dispute concerns the exchanging of [real] produce for [gold] denarii too.  Now, on the view that the dispute refers only to the exchange of sela's for denarii, instead of stating the dispute in reference to the exchange of sela's for denarii, let it be stated in reference to the exchange of sela's for sela's!  — If the dispute were stated thus, I might have thought that it applies only thereto, but as for exchanging sela's for [gold] denarii, Beth Hillel concede to Beth Shammai that gold ranks as produce in respect to silver, and therefore such redemption is not permissible. Hence we are taught otherwise. Come and hear: If one exchanges a sela' of second tithe in Jerusalem,  Beth Shammai say: He must exchange the whole sela' for [copper] coins.  But Beth Hillel rule: He must change it into a silver shekel, and [retain] a shekel's worth of [copper] coins.  Now, if silver may be redeemed with [copper] Perutahs, and we do not say. [It may be exchanged into] money once, but not twice: are we to say it in respect of gold, which is more valuable?  — Said Raba: Do you raise an objection from Jerusalem! Jerusalem is different, since it is written thereof, And thou shalt bestow that money [sc. in Jerusalem] for whatsoever thy soul lusteth after, for oxen, for sheep, [etc.]. Come and hear: 'If one changes a sela''s worth of second tithe [copper] coins, Beth Shammai rule: the full sela''s worth of coins must be changed.  But Beth Hillel rule: He must change only a shekel's worth into silver, and retain a shekel's worth of coins'?  — Hence [we must assume that] all agree, that 'the silver … silver' is an extension, including even a second redemption of money.  But if a dispute between R. Johanan and Resh Lakish was stated, It was stated thus: One maintains: Their dispute concerns the changing of sela's into [gold] denarii only. Beth Shammai hold: We forbid this as a precautionary measure,