《太平广记·卷一百八十七·职官》
唐宪宗李纯元和年间监察御史元禛与宫中使臣宦官争占驿厅，元稹被宦官所污辱。皇上才下有命令性质的诏书，规定节度使、观察使、台官和中使，先到驿馆的，得住上厅，定下这种规矩。
元和中，元稹为监察，与中使争驿厅，为其所辱，始有敕：节度观察使台官与中使，先到驿者，得处上厅。
During the reign of Li Chun, Emperor Xianzong of the Tang Dynasty, Yuan Zhen, the Yushi Censor, and the eunuch of the palace envoy competed for the post house. Yuan Zhen was insulted by the eunuch. Only then did the emperor issue an edict, stipulating that the Jiedushi, the observing envoy, the Taiguan and the eunuch would first go to the post house. The one who can live in the hall sets this rule.