In the Warring States Period, Duke Wei of the State of Qi accepted the suggestion of his minister Zou Ji and decided to gather widely opinions on ruling the state. He issued an order: "Regardless of whether a man is a minister or a commoner, anyone who points out my faults to my face will get the first prize; anyone who criticizes me in memorial will get the second prize; anyone who criticizes me in pubic will get the third prize." When they learned about this, the people flocked to the duke's palace to present their opinions. The area in front of the palace gate was as busy as a market.

From this story is derived the idiom which describes a very busy scene.