(133) باب الْمَرْأَةِ تَغْسِلُ ثَوْبَهَا الَّذِي تَلْبَسُهُ فِي حَيْضِهَا
'Aishah said:
One of us would have a shirt in which she would menstruate and in it she became sexually defiled. Then if she ever saw any drop of blood in it, she would rub it off by applying her saliva.
Reference: Sunan Abi Dawud 364
In-book reference: Book 1, Hadith 364
English translation: Book 1, Hadith 364