Hide one's edge: metaphor for sharpness or talent. Not showing vitality or talent. More refers to deliberately concealing one's talents, ambitions, etc.

A sharp sword does not show its edge: the tip of a sword is a metaphor for the talent or scheming revealed; Lou: Performing. Talented or scheming, that's all.

Wealth does not reveal white dew: dew; White: another name for silver. It used to mean that you can't reveal the money to others. Now it means that the money you carry with you is not revealed in front of people.