Bekhorot 50B

רב יהודה אמר רב אסי: כל ״כסף״ האמור בתורה סתם ⁠— כסף צורי, ושל דבריהם ⁠— כסף מדינה.

§ Rav Yehuda says that Rav Asi says: Every sum of money stated in the Torah without specifying that it is in shekels is referring to silver dinars of Tyrian coinage, which have a high value. And every mention of coins in statements of the rabbis is referring to provincial coinage, which was worth roughly 1/8th of Tyrian coinage.

וכללא הוא? והרי טענה, דכתיב: ״כי יתן איש אל רעהו כסף או כלים לשמור״,

The Talmud challenges: And is it an established principle that all money mentioned in the Torah is a silver dinar of Tyrian coinage? But there is the case of one who admits to part of a claim that he has not returned a deposit or loan, where it is written: “If a man deliver to his neighbor money or vessels to guard and it is stolen out of the man’s house…the cause of both parties should come before the judges” (Exodus 22:6–8). This teaches that the case is brought to a court, where the defendant must take an oath.

ותנן: שבועת הדיינין ⁠— הטענה שתי כסף!

And we learned in a Mishnah with regard to one who admits to part of a claim (Shevuot 38b): The oath administered by the judges to one who admits to part of a claim is administered only when the claim is for at least two silver ma’a, and the defendant’s admission is to at least the value of one peruta. If every sum of money mentioned in the Torah is referring to Tyrian coinage, how did the rabbis arrive at the amount of two ma’a in this case?

שאני התם, דכתיב: ״כסף או כלים״, מה כלים שנים ⁠— אף כסף שנים, ומה כסף דבר חשוב ⁠— אף כלים דבר חשוב.

The Talmud explains: There, the halakha is derived from a juxtaposition, as the “money” mentioned in the verse is similar to “vessels”: Just as the word “vessels” indicates at least two, so too, “money” is referring to at least two coins. And just as money is a significant item, i.e., silver ma’a, so too, the vessels must be a significant item. Rav Asi, by contrast, is referring to a mention of money where there is no juxtaposition.