The phrase "ancient proverb" refers to a wise saying or piece of advice that has been passed down through many generations and has stood the test of time. Full definition
In fact, there are two ancient proverbs from the Italian city of Florence that say, if you want to live a healthy and active life, drink whey, and, if everyone were raised on whey, doctors would be bankrupt. (bodybuildingforyou.com)
Dr Curry would have done well to remember that ancient proverb qui cum canibus concumbunt cum pulicibus surgent, or as we would say today: If you lie down with dogs, you will get up with fleas. (realclimate.org)
There's an ancient proverb that sums up these assumptions, «If I love you more will you love me less.» (entrepreneur.com)