Assalaamu alaykum. Please do not cite other fatwas. Why does the divorce of a woman who is menstruating not count? What is the wisdom behind it? Is the husband required to divorce her after her menses end?

All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger. 

A divorce issued during the wife's menstruation is prohibited, yet valid, and takes effect according to the majority of scholars. Shaykhul-Islam Ibn Taymiyyah and those who concurred with him, held that a divorce issued during menstruation does not take effect.

As for the wisdom behind it, it was said that it (divorce during menstruation) prolongs the woman's ‘Iddah (post-divorce waiting period). It was also said that it is because the time of menstruation tends to be a time of aversion (between spouses) and refraining from sexual intercourse. It was also said that there is no known wisdom behind it and that this falls under the category of matters determined through divine revelation that must be accepted as is without need of rationale.

The majority of scholars held that it is recommended for a husband who issues a revocable divorce while his wife is experiencing menstruation to revoke the divorce and take his wife back in marriage until her menses end and she then menstruates again and her menses then end. If he wishes to retain the marriage bond afterwards, he can do so; otherwise, he can divorce her (while she is in a state of ritual purity without having sexual intercourse with her) if he wishes, and he is not obliged to divorce her. Some scholars maintained that the husband is legislatively obliged to revoke the divorce issued during menstruation.

Finally, the divorce that conforms to the sharee'ah is that which is issued while the wife is in a state of purity (non-menstruating) without having had sexual intercourse with her (since she became purified from menses).

For more benefit, please refer to fataawa 84647and 82735.

Allaah knows best.