《周礼·秋官司寇·士师&朝士》
士师的职责，掌管有关五禁之法，以辅助刑罚禁止民众为非作歹：一是有关王宫的禁令，二是有关官府的禁令，三是有关都城的禁令，四是有关都城外田野的禁令，五是有关军中的禁令。都摇响木铎宣示于外朝，并书写出来悬挂在各处的闾巷门前。
士师之职，掌国之五禁之法，以左右刑罚，一曰宫禁，二曰官禁，三曰国禁，四曰野禁，五曰军禁，皆以木铎徇之于朝，书而县于门闾。
The responsibilities of the Protector of the Law were to manage the methods of Five Prohibitions, to assist the punishments and prohibit the people from doing evil and committing crimes: The first one was the prohibition related to the royal palace; the second one was the prohibition related to the government offices; the third one was the prohibition related to the capital city; the fourth one was the prohibition related to the countryside outside of the capital city; the fifth one was the prohibition related to the military. They all rang wooden bells outside the court to announce it and wrote it on documents and hung it in front of the gates of each lane.