Sahih al-Bukhari 309
Narrated `Aisha:
Once one of the wives of the Prophet (ﷺ) did I`tikaf along with him and she was getting bleeding in 
between her periods. She used to see the blood (from her private parts) and she would perhaps put a 
dish under her for the blood. (The sub-narrator `Ikrima added, `Aisha once saw the liquid of safflower 
and said, "It looks like what so and so used to have.")
حَدَّثَنَا إِسْحَاقُ، قَالَ حَدَّثَنَا خَالِدُ بْنُ عَبْدِ اللَّهِ، عَنْ خَالِدٍ، عَنْ عِكْرِمَةَ، عَنْ عَائِشَةَ، أَنَّ النَّبِيَّ صلى الله عليه وسلم اعْتَكَفَ مَعَهُ بَعْضُ نِسَائِهِ وَهْىَ مُسْتَحَاضَةٌ تَرَى الدَّمَ، فَرُبَّمَا وَضَعَتِ الطَّسْتَ تَحْتَهَا مِنَ الدَّمِ‏.‏ وَزَعَمَ أَنَّ عَائِشَةَ رَأَتْ مَاءَ الْعُصْفُرِ فَقَالَتْ كَأَنَّ هَذَا شَىْءٌ كَانَتْ فُلاَنَةُ تَجِدُهُ‏.‏