买椟还珠

A man from the state of Chu wanted to sell a precious pearl in the state of Zheng. He made a casket（小箱，棺材） for the pearl out of the wood from a magnolia（木兰） tree, which he fumigated（熏制） with spices. He studded the casket with pearls and jade, ornamented it with red gems and decorated it with kingfisher（翠鸟） feathers. A man of the state of Zheng bought the casket and gave him back the pearl.

Too luxuriant（丰富的，奢华的） decoration usually supersedes（取代） what really counts. This man from Chu certainly knew how to sell a casket but he was no good at selling his pearl. And the man of Zheng didn't know which is really valuable.