Abu Ishaq al-Sabay'ai' أبو إسحاق السبيعي عمرو بن عبد الله · The Book of Divorce

"Abdullah has divorced his wife while she was menstruating." He said: "Tell 'Abdullah to take her back, then leave her until she becomes pure from this menstrual period, then menstruates again, then when she becomes pure again, if he wishes he may separate from her before having intercourse with her, or if he wishes he may keep her. This is the time when Allah, the Mighty and Sublime, has stated that women may be divorced."

"While Abu Hurairah and I were with Ibn 'Abbas, a woman came and said that her husband had died while she was pregnant, then she had given birth less than four months after the day he died. Ibn 'Abbas said: '(You have to wait) for the longer of the two periods.'" Abu Salamah said: "A man from among the Companions of the Prophet told me that Subai'ah Al-Aslamiyyah came to the Messenger of Allah and said that her husband died…

"A woman came to the Prophet and asked him about that, and he said: 'During the Jahiliyyah, if her husband died, one of you would stay (in mourning) for a year, then she would throw a piece of dung then come out. Rather it (the mourning period) is four months and ten days, until the term prescribed is fulfilled.'"