Sahih al-Bukhari 2037
Book 33: Retiring to a Mosque for Remembrance of Allah (I'tikaf) · Narrated by `Aisha
Arabic
حَدَّثَنَا قُتَيْبَةُ، حَدَّثَنَا يَزِيدُ بْنُ زُرَيْعٍ، عَنْ خَالِدٍ، عَنْ عِكْرِمَةَ، عَنْ عَائِشَةَ ـ رضى الله عنها ـ قَالَتِ اعْتَكَفَتْ مَعَ رَسُولِ اللَّهِ صلى الله عليه وسلم امْرَأَةٌ مِنْ أَزْوَاجِهِ مُسْتَحَاضَةٌ، فَكَانَتْ تَرَى الْحُمْرَةَ وَالصُّفْرَةَ، فَرُبَّمَا وَضَعْنَا الطَّسْتَ تَحْتَهَا وَهْىَ تُصَلِّي.
English translation
Narrated `Aisha:One of the wives of Allah's Messenger (ﷺ) practiced I`tikaf with him while she had bleeding in between her periods and she would see red (blood) or yellowish traces, and sometimes we put a tray beneath her when she offered the prayer
Reference: Sahih al-Bukhari 2037, Book of Retiring to a Mosque for Remembrance of Allah (I'tikaf). English translation by Dr. Muhammad Muhsin Khan.