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The Mishna had stated: One who steals from his fellow something worth a perutah and swears falsely is obligated to bring it to him, even to Media.
What is the significance of Media?
The Vilna Gaon (Kol Eliyahu; Kiddushin 12a) explains based on the following verse [Yeshaya 13:17]: Behold I stir up Media against them, who do not value silver, and do not desire gold. The thief must travel even to Media, a place where a perutah is completely insignificant because of the abundance of gold and silver that is found there. Nevertheless, the thief must go there and return the money that he stole.
This is why Shmuel (Kiddushin 12a) ruled that if someone betroths a woman with a date, even if a kur of dates is only worth a dinar, we say that she is betrothed, as a single date might be worth a perutah in (the country of) Media. Precisely in Media, where money is insignificant, that is where it is possible that one will receive a perutah in exchange of one date.
The Nitzotzei Ohr adds on his words: This is why the Gemora there mentions dates, for dates there were very expensive. That is why beer there was made from barley and not from dates, as we find the Gemora discusses the beer from Media. For this reason, one was prepared to pay a perutah for one date.