In this verse we come to another question which is about menstruation saying: ``They ask you concerning menstruation? Say: It is a harm. So keep aloof from women during their periods, and do not approach them for sexual intercourse, until they are clean again.''
Sexual intercourse in such a condition is dangerous for both of the sexes. It may create abhorrence in them, and result in barrenness of either of the couple; and also for many medical reasons, sexual affairs in the menstrual period is also forbidden by physicians too.
The verse then adds: ``When they have cleansed come to them as Allah has commanded you.'' This is because physical cleanliness and purity makes for health; bodily as well as spiritual.