Sahih Bukhari
Menstrual Periods
Volume: 001 / Book Number: 006 / Hadith Number: 297
Narrated Um Salama:
While I was laying with the Prophet under a single woolen sheet, I got the menses. I slipped away and put on the clothes for menses. He said, "Have you got "Nifas" (menses)?" I replied, "Yes." He then called me and made me lie with him under the same sheet.