leave the area of intimacy uncovered, lest he see blood or the like that he finds unpleasant, causing him to feel repulsed by her and affecting his disposition toward her even in the future. This is why, as part of the Prophet’s ﷺ wisdom, he would instruct the woman to wear a waist-wrapper.
If he has intercourse during menstruation, this entails sin, disobedience, and punishment.
But is expiation required of him or not?
This depends on the authenticity of the hadith reported on this matter, concerning which the scholars differ. Whoever considers the hadith authentic holds that it must be acted upon. The expiation is one dinar or half a dinar—either as a choice between the two, or according to the stage of menstruation. That is, a distinction is made between intercourse near the end of menstruation, when the bleeding has become lighter and the desire for intercourse has intensified—in which case the expiation is half a dinar—and intercourse at its beginning, when the bleeding is at its heaviest—in which case it is one dinar.
However, allowing a choice between the two presents a difficulty: it is customary in prescribed expiations that an obligatory expiation cannot consist of the same type in either a full or partial amount. Choice is only given between two different things, such as feeding, clothing, and freeing a slave in the expiation for an oath. But giving a choice between two things of the same type—except that one is greater and the other lesser—has not otherwise occurred.
The answer to this is that Allah has the right to decree whatever He wills. Thus, if He gives the servant the choice between one dinar and half a dinar, this is from His mercy: whoever seeks what is more virtuous may give one dinar in charity, while whoever seeks to fulfill the obligation may give half a dinar in charity.