Sahih Bukhari
Sahih Bukhari Volume 001, Book 006, Hadith Number 327.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 06. Menstrual Periods
Narated By 'Aisha : The Prophet said to me, "Give up the prayer when your menses begin and when it has finished, wash the blood off your body (take a bath) and start praying."