An adage is a saying that becomes widely accepted as truth over time. Adages are usually observances of life and behavior that express a general truth.
Poor Richard's Almanack was published yearly from 1732 to 1758 by Benjamin Franklin. It contained many adages that are commonly used today.
Here are some examples:
Adages can come from a variety of sources; but, what they all have in common, is that they may have started out as a saying but they are now accepted as a truth of life.