Leviticus 15:19, 25

“ ‘When a woman has her monthly period, she is unclean for seven days; anyone who touches her will be unclean until evening.

“ ‘If a woman has a loss of blood for many days and it is not during her regular monthly period, or if she continues to have a loss of blood after her regular period, she will be unclean, as she is during her monthly period. She will be unclean for as long as she continues to bleed.