18. If a man has sexual relations with a woman, they shall both bathe in water and be unclean until evening.
19. When a woman has a flow of blood from her body, she shall be in a state of menstrual uncleanness for seven days. Anyone who touches her shall be unclean until evening.
20. Anything on which she lies or sits during her menstrual period shall be unclean.
21. Anyone who touches her bed shall wash his garments, bathe in water, and be unclean until evening.