Abdullah bin Umar reported,

I divorced my wife during the time of the Messenger of Allah ﷺ while she was menstruating. Umar mentioned this to the Messenger of Allah ﷺ, who said, "Order him to take her back, then leave her until she becomes pure, then menstruates again. When she becomes pure, let him divorce her before having relations with her, or keep her. That is the waiting period Allah commanded for divorcing women."Ubaydullah said, I asked Nafi, "What became of that pronouncement of divorce?"He replied, "It was counted as one."

Muslim 3654

Sahih

حدثنا محمد بن عبد الله بن نمير حدثنا أبي حدثنا عبيد الله عن نافع

عن ابن عمر قال

طلقت امرأتي على عهد رسول الله ﷺ وهي حائض فذكر ذلك عمر لرسول الله ﷺ فقال مره فليراجعها ثم ليدعها حتى تطهر ثم تحيض حيضة أخرى فإذا طهرت فليطلقها قبل أن يجامعها أو يمسكها فإنها العدة التي أمر الله أن يطلق لها النساء قال عبيد الله قلت لنافع ما صنعت التطليقة قال واحدة اعتد بها

مسلم 3654صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Muslim
Book
Divorce
Chapter
Prohibition of divorcing a menstruating woman without her consent, and that if one does so the divorce still takes effect and he is commanded to take her back
Numbering
Darussalam 3654
Muslim 3654