In the Han Feizi, a man of Chu goes to Zheng to sell a pearl. He makes a casket of magnolia wood, perfumes it with cinnamon and pepper, and decorates it with pearls and jade, red gems and kingfisher feathers. A man of Zheng buys the casket and gives back the pearl.
The idiom mai du huan zhu, to buy the casket and return the pearl, means to value the outside and neglect the substance.