Lev 15:19-20, Deu 25:5 | ESV | STEP | When a woman has a discharge , and the discharge in her body is blood , she shall be in her menstrual impurity for seven days , and whoever touches her shall be unclean until the evening .

Leviticus 15:19-20

19 “When a woman has a discharge, and the discharge in her body is blood, she shall be in her menstrual impurity for seven days, and whoever touches her shall be unclean until the evening. 20 ^aAnd everything on which she lies during her menstrual impurity shall be unclean. Everything also on which she sits shall be unclean.

Deuteronomy 25:5

Laws Concerning Levirate Marriage

5 ^b“If brothers dwell together, and one of them dies and has no son, the wife of the dead man shall not be married outside the family to a stranger. Her ^chusband’s brother shall go in to her and take her as his wife and perform the duty of a husband’s brother to her.