The law governing sexual intercourse during a woman’s menstrual period states: “Where a man lies down with a menstruating woman and does lay bare her nakedness, he has exposed her source, and she herself has laid bare the source of her blood. So both of them must be cut off from among their people.” (Lev. 20:18; 18:19,

The prohibition on sexual intercourse during a woman’s menstrual period was a purposeful restriction. It protected a man from becoming religiously unclean by contact with the blood of a menstruating woman. And it took into consideration the woman’s physical and biological limitations. When obeyed, this law evidently contributed to the health of Israelite women. Says Dr. Jacob B. Glenn in his book The Bible and Modern Medicine: “The female genital tract, especially during periods of lowered resistance (menstruation), is particularly vulnerable to irritation and stimulation; hence, the strict law among Jewish people forbidding cohabitation during this period.”