The Foolish Old Man of the North Mountain, nearly ninety years of age, lived behind two high mountains. He was unhappy about the fact that the mountains blocked his way to the south, so he called the whole family to level the two mountains.While they were working, The Wise Old Man at the River Bend stopped the old man. He laughed and said, "How unwise you are! At your age, old and feeble as you are, you cannot even remove one hair on the mountain, let alone so much earth and so many rocks!"

In the Han Dynasty (hàn cháo 汉朝), there was a Taoist called Wei Boyang who wrote a book on the making of pills of immortality. In this book there is the following line:” Fish eyes can’t be passed off as pearls, and bitter flea-bane can’t pretend to be tea.” Fish eyes look like pears, but are valueless.This idiom is used to mean passing off the sham as the genuine.