According to Xijing Miscellanies, Emperor Gaozu Liu Bang led his troops into Xianyang, Qin Dou, and sent troops to protect Qin Gong. Liu Bang visited the treasury and saw countless treasures, especially a precious mirror. The mirror body is square, four feet wide and five feet nine inches high. It is bright and crystal clear. People stand in front of the mirror, but the figure in the mirror is upside down; If you press your heart in front of the mirror, you can clearly see your stomach and internal organs. If a person has a disease, then looking in the mirror can find out the root of the disease. It is said that Qin Shihuang often used this precious mirror to check the concubines, ladies-in-waiting and courtiers in the palace. If one of them has infidelity and evil thoughts, the mirror will show his bravery and inner abnormality. Of course, such people will be killed immediately.
Liu bang ordered all the treasures in the palace to be closed, and then discussed how to deal with them when Xiang Yu came. Xiang Yu later led the troops to burn Qin Gong in Xianyang, and this precious mirror was also taken away by him and brought to Pengcheng in the east. Since then, the precious mirror has gone missing. Also known as "mirror hanging high".