Sahih muslim:938c Chapter: The prohibition of divorcing a menstruating woman without her consent; If a man breaks this rule, it still counts as a divorce, and he should be ordered to take her back Book 18, Hadith 85

Umm `Atiyya (Allah be pleased with her) reported that Allah’s Messenger (ﷺ) had said: A woman must not observe mourning for one who had died for more than three (days) except for four months and ten days in the case of her husband. And she must not wear a dyed garment except one of the types made of dyed yarn, or apply collyrium, or touch perfume except a little perfume or incense, when she has been purified after her courses.