The GRA wrote a sefer on Geometry called Ayil Meshulash. Sometimes some secular education helps to understand a mishna.
הזהב קונה את הכסף. The Chachomim said that miderabonon the commodity acquires the currency (meshicha koneh). Gold is the commodity and not the currency. Why? There is a law in economics called Gresham’s Law which says, the bad coins drive out the good coins from circulation. Gold is the good coin which is not spent but hoarded. Silver with less value is spent, so silver is currency and gold is the commodity.
Menu