Sahih Bukhari Volume 003, Book 032, Hadith Number 241.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 32. Praying at Night In Ramadhan (Taraweeh)
Narated By 'Aisha : With the start of the last ten days of Ramadan, the Prophet used to tighten his waist belt (i.e. work hard) and used to pray all the night, and used to keep his family awake for the prayers.