Concerning a man who divorced his wife while she was menstruating, he said, "Do you know Abdullah bin Umar? He divorced his wife while she was menstruating, so Umar asked the Prophet ﷺ about it, and he ordered him to take her back and then count her waiting period afresh."I asked him, "Does that pronouncement of divorce count?"He replied, "Stop. What do you think? If a man falls short and acts foolishly, does that exempt him?"
أخبرنا قتيبة قال حدثنا حماد عن أيوب عن محمد عن يونس بن جبير قال
عن رجل طلق امرأته وهي حائض فقال هل تعرف عبد الله بن عمر فإنه طلق امرأته وهي حائض فسأل عمر النبي ﷺ فأمره أن يراجعها ثم يستقبل عدتها فقلت له فيعتد بتلك التطليقة فقال مه أرأيت إن عجز واستحمق
Reported by Muslim, in the Book of Divorce, chapter on the prohibition of divorcing a menstruating woman without her consent, etc, hadith 7/1471, from Qutayba, and by Bukhari, in the Book of Divorce, chapter on taking back a menstruating woman, hadith 5333 (chapter, if a menstruating woman is divorced, does that divorce count, hadith 5252), from the hadith of Muhammad bin Sirin, with the same chain. It is also found in al-Kubra, hadith 5592.Hammad here is Ibn Zayd.