20, 21. What regulations cover cleanness and proper hygiene?

²⁰ Laws on cleanness (11:1–15:33). This section deals with ceremonial and hygienic cleanness. Certain animals, both domestic and wild, are unclean. All dead bodies are unclean and cause those who touch them to become unclean. The birth of a child also brings uncleanness and requires separation and special sacrifices.

²¹ Certain skin diseases, such as leprosy, also cause ceremonial uncleanness, and cleansing is to apply not only to persons but even to clothing and houses. Quarantining is required. Menstruation and seminal emissions likewise result in uncleanness, as do running discharges. Separateness is required in these cases, and on recovery, in addition, the washing of the body or offering of sacrifices or both are required.

³⁴ (6) Relativity in guilt and punishment. Not all sins and sinners were considered in the same light. The higher the office, the greater the responsibility and penalty for sin. Willful sin was punished more severely than unintentional sin. Penalties were often graded according to ability to pay. This principle of relativity also applied in fields other than sin and punishment, such as in ceremonial uncleanness.​—Lev. 4:3, 22-28; 5:7-11; 6:2-7; 12:8; 21:1-15; Luke 12:47, 48; Jas. 3:1; 1 John 5:16.