Sahih al-Bukhari, Hadith 311 ⓘ
Narrated `Aisha: One of the mothers of the faithful believers (i.e. the wives of the Prophet ) did I`tikaf while she was having bleeding in between her periods.
حَدَّثَنَا مُسَدَّدٌ، قَالَ حَدَّثَنَا مُعْتَمِرٌ، عَنْ خَالِدٍ، عَنْ عِكْرِمَةَ، عَنْ عَائِشَةَ، أَنَّ بَعْضَ، أُمَّهَاتِ الْمُؤْمِنِينَ اعْتَكَفَتْ وَهْىَ مُسْتَحَاضَةٌ.
also referenced under: Book 6, Hadith 16 (In-Book) & Volume 1, Book 6, Hadith 308 (USC-MSA)