(2) باب إِذَا طُلِّقَتِ الْحَائِضُ يُعْتَدُّ بِذَلِكَ الطَّلاَقِ
Narrated Anas bin Seereen:
Ibn `Umar said: "I divorced my wife while she was menstruating. `Umar mentioned that to the Prophet . The Prophet (ﷺ) said, (to my father), "Let your son take her back." I asked (Ibn `Umar), "Is such a divorce counted (i.e. as one legal divorce)?" Ibn `Umar said, "Of course." Narrated Yunus bin Jubair: Ibn `Umar said, "The Prophet (ﷺ) said to `Umar, 'Order him (Ibn `Umar) to take her back.' " I asked, "Is such a divorce counted (as one legal divorce)?" Ibn `Umar said, "What do you think if someone becomes helpless and foolish?"
Reference: Sahih al-Bukhari 5252
In-book reference: Book 68, Hadith 2
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 7, Book 63, Hadith 179