Sahih al-Bukhari 5253

Arabic

وَقَالَ أَبُو مَعْمَرٍ حَدَّثَنَا عَبْدُ الْوَارِثِ، حَدَّثَنَا أَيُّوبُ، عَنْ سَعِيدِ بْنِ جُبَيْرٍ، عَنِ ابْنِ عُمَرَ، قَالَ حُسِبَتْ عَلَىَّ بِتَطْلِيقَةٍ‏.‏

English translation

Narrated Ibn `Umar:(Divorcing my wife during her menses) was counted as one legal divorce

Reference: Sahih al-Bukhari 5253, Book of Divorce. English translation by Dr. Muhammad Muhsin Khan.