Smith argues that a nation's wealth stems from the goods and services it produces, rather than the amount of money it collects. Specialization increases wealth through a dramatic increase in productivity. A market economic system is the most efficient method for setting prices and creating wealth. Money is a medium for exchange and has no inherent value of its own. International trade makes both nations in a transaction better off.
Eamon Butler, Condensed Wealth of Nations, Adam Smith Institute 2011: https://static1.squarespace.com/static/56eddde762cd9413e151ac92/t/56fbaba840261dc6fac3ceb6/1459334065124/Condensed_Wealth_of_Nations_ASI.pdf