Menstruation

A woman was considered ceremonially unclean during menstruation

Leviticus 15:19–23 See also Leviticus 12:1–5, Leviticus 15:25–30; Isaiah 30:22

When a woman has a discharge consisting of blood from her body, she will be unclean due to her menstruation for seven days, and anyone who touches her will be unclean until evening. Anything on which she lies or sits during her menstruation will be unclean, and anyone who touches her bed must wash his clothes and bathe with water, and he will be unclean until evening. Whoever touches any furniture on which she was sitting must wash his clothes and bathe with water, and he will be unclean until evening. And whether it is a bed or furniture on which she was sitting, whoever touches it will be unclean until evening.

Sexual intercourse during menstruation forbidden

Leviticus 18:19 See also Leviticus 20:18; Ezekiel 18:5–6, Ezekiel 22:10

You must not approach a woman to have sexual relations with her during her menstrual period.

The discomfort of menstruation

Genesis 31:35