He said that whenever Ibn Umar was asked about a man who divorced his wife while she was menstruating, he would reply, "If he divorced her once or twice, then the Messenger of Allah ﷺ commanded him to take her back and keep her until she menstruates again, then becomes pure, and then divorces her before touching her. But if he divorced her three times, then he has disobeyed Allah in what He commanded regarding the divorce of his wife, and his wife has become irrevocably separated from him."
أخبرنا علي بن حجر قال أنبأنا إسمعيل عن أيوب
قال كان ابن عمر إذا سئل عن الرجل طلق امرأته وهي حائض فيقول أما إن طلقها واحدة أو اثنتين فإن رسول الله ﷺ أمره أن يراجعها ثم يمسكها حتى تحيض حيضة أخرى ثم تطهر ثم يطلقها قبل أن يمسها وأما إن طلقها ثلاثا فقد عصيت الله فيما أمرك به من طلاق امرأتك وبانت منك امرأتك