It refers to the practice form in which Taoist practitioners practice Lei Fa or Yu Shu Dao on the sixth and third day of each month and in the sixth month of the lunar calendar, and recite Yu Shu Bao Jing.

Lei Zheng made Xin Tianjun, the great god, the master book of Lei Department, the judge of Wu Lei Department, and the director of the Nine-Day School Examination Department, Zhai Lei, also known as Xin Zhai.