"If a woman has a discharge, and the discharge from her body is blood, she shall be set apart seven days; and whoever touches her shall be unclean until evening.
Leviticus 15:19
Surrounding context
15:18 Also, when a woman lies with a man, and there is an emission of semen, they shall bathe in water, and be unclean until evening.
15:19 "If a woman has a discharge, and the discharge from her body is blood, she shall be set apart seven days; and whoever touches her shall be unclean until evening.
15:20 Everything that she lies on during her impurity shall be unclean; also everything that she sits on shall be unclean.