《后汉书·列传·郎顗襄楷列传下》
应在五月丙午，派太尉持盾牌斧头，建井韄，在玉板上写祝辞，引白气之异，在西郊自我检讨，对皇天谢罪，消灭妖气。
宜以五月丙午，遣太尉服干戚，建井，书玉板之策，引白气之异，于西郊责躬求愆，谢咎皇天，消灭妖气。
On May Bingwu, the Grand Marshal should be sent to hold a shield and an axe, build a Jingmao chariot, write an incantation on a jade tablet, induce the wonder of white energy, introspect in the western suburbs, apologize to the Emperor, and eliminate the evil spirits.