Sahih al-Bukhari 310
Book 6: Menstrual Periods · Narrated by `Aisha
Arabic
حَدَّثَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا يَزِيدُ بْنُ زُرَيْعٍ، عَنْ خَالِدٍ، عَنْ عِكْرِمَةَ، عَنْ عَائِشَةَ، قَالَتِ اعْتَكَفَتْ مَعَ رَسُولِ اللَّهِ صلى الله عليه وسلم امْرَأَةٌ مِنْ أَزْوَاجِهِ، فَكَانَتْ تَرَى الدَّمَ وَالصُّفْرَةَ، وَالطَّسْتُ تَحْتَهَا وَهْىَ تُصَلِّي.
English translation
Narrated `Aisha:"One of the wives of Allah's Messenger (ﷺ) joined him in I`tikaf and she noticed blood and yellowish discharge (from her private parts) and put a dish under her when she prayed
Reference: Sahih al-Bukhari 310, Book of Menstrual Periods. English translation by Dr. Muhammad Muhsin Khan.