I said to Ibn Umar, "A man divorced his wife while she was menstruating."He replied, "Do you know Abdullah bin Umar? He divorced his wife while she was menstruating, so Umar went to the Prophet ﷺ and asked him about it. The Prophet instructed him to take her back and then let her begin her waiting period afresh."I said to him, "When a man divorces his wife while she is menstruating, is that pronouncement of divorce counted?"He answered, "Of course. What else? Even if he acts incapably and foolishly?"
و حدثني يعقوب بن إبراهيم الدورقي عن ابن علية عن يونس عن محمد بن سيرين
قلت لابن عمر رجل طلق امرأته وهي حائض فقال أتعرف عبد الله بن عمر فإنه طلق امرأته وهي حائض فأتى عمر النبي ﷺ فسأله فأمره أن يرجعها ثم تستقبل عدتها قال فقلت له إذا طلق الرجل امرأته وهي حائض أتعتد بتلك التطليقة فقال فمه أو إن عجز واستحمق