First of all, we would like to stress that menstruating women are allowed to attend the `Eid prayer without participating in the prayer but just to witness it. The significance of this is meant for encouraging Muslims to gather at one time and share the blessings of this day and get to feel happy in the broader sense.
Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states the following: Traditionally, most of the Islamic scholars and jurists are of the opinion that women in a state of hayd (menstruation) are not permitted to enter or stay in the mosque. However, on a closer look at the issue from within the sources and evidence presented, it can be clearly seen that such an absolute ban is not based on any incontrovertible texts or proofs. Reports that are cited to justify such ban are considered either weak or dubious, or at best questionable as well as contradicted by other reports and ascertainable facts.
When faced with such ambiguities and doubts, we always have recourse to the original rule of permission, which can only be revoked in case of a categorical prohibition. It should also be pointed out that even some of the most prominent scholars—who, otherwise prohibit women in state of menstruation from staying in the mosque—allow them to do so in case of a genuine necessity. Attending classes for gaining essential Islamic knowledge undoubtedly falls in this category, especially in a predominantly non-Muslim society like ours in North America, where in many cities mosques are the only places where such education is imparted. By barring women from attending such classes or lectures in mosques, we will be depriving them of the only opportunity they may have for gaining essential religious knowledge, which is the life-blood of a vibrant Islamic community.
The opinion that women in case of necessity—not necessarily a dire necessity (darurah)—can enter and stay in the mosque is the view held by such authentic scholars and thinkers as Ibn Taymiyyah and others.
On the other hand, the view that women in a state of menstruation are permitted to enter and stay in the mosque is held by scholars such as al-Muzani, Dawud az-Zahiri, Ibn Hazm and others. The last mentioned view is based on the report from `A’ishah that the Prophet (peace and blessings be upon him) allowed a woman who had converted to Islam—who apparently had no place go—to stay inside the mosque, where she set up a little tent for that purpose. It is common knowledge that women do menstruate, and if it had been prohibited for women to enter or stay in the mosque in a state of menstruation, the Prophet (peace and blessings be upon him) certainly would not have allowed her to stay inside the mosque.
Those who hold the view that the women in state of menstruation are not permitted to enter and stay in the mosque compare menstruation with janabah (post-sexual impurity) as a major defilement. However, it is an established fact that the Prophet (peace and blessings be upon him) lodged the poor emigrants in the mosque. They were known as the people of as-Suffah. Men may occasionally experience nocturnal emissions. Yet, we are not told anywhere that the Prophet (peace and blessings be upon him) ever told them to get out of the mosque in such a state.
It is well known principle of Islamic jurisprudence that failure to explain something when it is needed shall be deemed as an indication of permission. How could the Prophet (peace and blessings be upon him) fail to communicate to the people of as-Suffah and to the woman he had lodged inside the mosque that they should leave the mosque when they are in a state of janabah or hayd?
Having said this, we must still urge the mosque authorities to arrange such classes or circles in areas of the mosque other than the prayer hall, such as basement or adjacent class rooms, etc., or provide special facilities for women to hear and see the speaker there. By doing so we remain within the consensus of scholars, as no one would ever object to that. If this is not practical because of constraints of space, then at least a small area in the main hall should be earmarked or cordoned off for women to sit behind or on the side of the regular prayer lines or musalla (prayer hall). When such conditions are observed, it is perfectly acceptable for women in a state of menstruation to attend `Eid and Jumu`ah sermons according to scholarly consensus.
In conclusion: We must never compromise the greater maslahah (welfare) of seeking essential Islamic education, which must take precedence over our pre-occupation with fiqh minutiae that are not based on any explicit textual proofs.