Language:
كتاب الطلاق
68  
Divorce
(2)
Chapter: Divorce during the menses is counted as one legal divorce.
(2)
باب إِذَا طُلِّقَتِ الْحَائِضُ يُعْتَدُّ بِذَلِكَ الطَّلاَقِ
Sahih al-Bukhari 5253

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.‏
Reference : Sahih al-Bukhari 5253
In-book reference : Book 68, Hadith 3
USC-MSA web (English) reference : Vol. 7, Book 63, Hadith 180
  (deprecated numbering scheme)