What is the Jianzhai 监斋？

Jianzhai (Supervisor of Offerings) is one of the "Three Masters," ranking second only to the High Priest (Gong).

The duties of Jianzhai are as follows:
To overall oversee the ritual charter, administer ceremonial regulations, correct the conduct of altar officials, and uphold the solemnity of the ritual hierarchy;
To meticulously detect improprieties, impart instructions with composure, maintain strictness and dignity, and ensure no negligence or abuse of authority, namely to supervise the codes and laws of ritual protocols.