According to Peake's commentary on the Bible, the Priestly Code specifies that individuals were washed before they could become members of the Jewish priesthood,[37] and similarly requires Levites to be cleansed before they assume their work.[38] Peake's commentary states that although Biblical rules regarding ritual purification following bodily discharges clearly have sanitary uses, they ultimately originated from the taboos against contact with blood and semen, due to the belief that these contained life, more than any other bodily fluid, or any other aspect of the body.[3]