Abu Ghallab Yunus bin Jubayr reported,

I said to Ibn Umar, "What about a man who divorces his wife while she is menstruating?"He replied, "Do you know Ibn Umar? Ibn Umar divorced his wife while she was menstruating, and Umar went to the Prophet ﷺ and mentioned that to him. He commanded him to take her back, and then when she became pure, if he wished to divorce her, he could divorce her then."I asked, "Was that counted as a divorce?"He answered, "What do you think if a man becomes incapable and acts foolishly?"

Bukhari 5258

Sahih

حدثنا حجاج بن منهال حدثنا همام بن يحيى عن قتادة

عن أبي غلاب يونس بن جبير قال

قلت لابن عمر رجل طلق امرأته وهي حائض فقال تعرف ابن عمر إن ابن عمر طلق امرأته وهي حائض فأتى عمر النبي ﷺ فذكر ذلك له فأمره أن يراجعها فإذا طهرت فأراد أن يطلقها فليطلقها قلت فهل عد ذلك طلاقا قال أرأيت إن عجز واستحمق

البخاري 5258صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Bukhari
Book
Divorce
Chapter
Whoever divorces and whether a man should say the divorce directly to his wife
Numbering
Darussalam 5258
Bukhari 5258