Most of the priests worked part-time in the temple, for one month in three. They had to be ritually clean for this month, bathing and shaving and abstaining from sex. The priesthood was at first not open to the lowest social classes, but from about 3,500 years ago people of all classes were allowed to hold a religious post.

The priesthood included administrators who ran the temple estates, clergy who carried out the daily ritual, or specialists such as astronomers who read the signs. The public were not allowed in the temple and did not take part in the services.