Sahih al-Bukhari, Volume 7, Book 63, Hadith 180 (USC-MSA) ⓘ
Narrated Ibn `Umar: (Divorcing my wife during her menses) was counted as one legal divorce.
وَقَالَ أَبُو مَعْمَرٍ حَدَّثَنَا عَبْدُ الْوَارِثِ، حَدَّثَنَا أَيُّوبُ، عَنْ سَعِيدِ بْنِ جُبَيْرٍ، عَنِ ابْنِ عُمَرَ، قَالَ حُسِبَتْ عَلَىَّ بِتَطْلِيقَةٍ.
also referenced under: Book 68, Hadith 3 (In-Book) & Hadith 5253 (DarusSalam)