Abdullah bin Umar said, "I divorced my wife while she was menstruating."Umar mentioned this to the Prophet ﷺ, and the Messenger of Allah ﷺ became angry. He then said, "Order him to take her back, and let her remain with him until she menstruates another time after the menstrual period in which he divorced her. Then if he still wishes to divorce her, let him do so when she is pure from menstruation and before he has touched her. That is the divorce as prescribed for the waiting period that Allah has commanded."Abdullah had pronounced one divorce, and it was counted as a divorce against her. Abdullah took her back as the Messenger of Allah ﷺ had ordered him.
أن عبد الله بن عمر قال: طلقت امرأتي وهي حائض. فذكر ذلك عمر للنبي ﷺ، فتغيظ رسول الله ﷺ ثم قال: مره فليراجعها حتى تحيض حيضة أخرى مستقبلة، سوى حيضتها التي طلقها فيها، فإن بدا له أن يطلقها، فليطلقها طاهرا من حيضتها قبل أن يمسها، فذلك الطلاق للعدة كما أمر الله وكان عبد الله طلقها تطليقة واحدة، فحسبت من طلاقها، وراجعها عبد الله كما أمره رسول الله ﷺ.
Narrated by Bukhari in the tafsir (4908), and Muslim in divorce (4:1471), both through Zuhri, who said, "Salim informed me," and he related it. The wording is Muslim's, and Bukhari does not have his statement, "and Abdullah was..." and so on. The narration of Salim bin Abdullah agrees with the narration of Nafi.However, someone other than Zuhri narrated it, from Salim, from Ibn Umar, that he divorced his wife while she was menstruating, and Umar mentioned this to the Prophet ﷺ, who said, "Tell him to take her back, then divorce her when she is pure or pregnant." Muslim narrated this from the hadith of Muhammad bin Abdul-Rahman (the freedman of the family of Talha), from Salim, and he related it.