Sahih Bukhari Volume 001, Book 006, Hadith Number 312.
Narated By 'Aisha : An Ansari woman asked the Prophet how to take a bath after finishing from the menses. He replied, "Take a piece a cloth perfumed with musk and clean the private parts with it thrice." The Prophet felt shy and turned his face. So pulled her to me and told her what the Prophet meant.