Abdullah bin Umar reported,

He divorced his wife with a single pronouncement of divorce while she was menstruating. Umar went and informed the Prophet ﷺ of what had happened.The Prophet ﷺ said to him, "Tell Abdullah to take her back. Then when she has bathed, let him leave her until she menstruates again. When she has bathed after this second period, he must not touch her until he divorces her. If he wishes to keep her, let him keep her. This is the waiting period which Allah commanded for the divorce of women."

أخبرنا محمد بن عبد الأعلى قال حدثنا المعتمر قال سمعت عبيد الله بن عمر عن نافع

عن عبد الله

أنه طلق امرأته وهي حائض تطليقة فانطلق عمر فأخبر النبي ﷺ بذلك فقال له النبي ﷺ مر عبد الله فليراجعها فإذا اغتسلت فليتركها حتى تحيض فإذا اغتسلت من حيضتها الأخرى فلا يمسها حتى يطلقها فإن شاء أن يمسكها فليمسكها فإنها العدة التي أمر الله عز وجل أن تطلق لها النساء