Likutei Moharan 23:13/ליקוטי מוהר"ן כ״ג:י״ג

113. [The following relates to section 5:] Salt, when it spoils, with what can it be preserved?… One who succumbs to the st ench of greed. Therefore, the expression “when it SaRya (spoils)” was used, for this is a term used in connection with idol worship, as in (Exodus 32:8), “SaRu (They have turned) quickly [from the way that I ordered them to follow].” This is because someone who is steeped in [the desire for] money worships all idolatry, as explained. And so, the idol of each idolatrous nation is etched onto its currency.

2Based on these teachings, the intelligent will understand how to explain the entire subject of “gold acquires silver, but silver does not acquire… copper acquires…. and the principle: That which is a coin and current is considered money” (Bava Metzia 44a). Study the entire subject there. And the subject of “whether money can be acquired through barter” (ibid. 45b), and also the subject of “something that is treated as money for something else” (Kiddushin 28a) —all will become clear to the wise based on this lesson and a few additional introductions.