Volume 3 · Book 32 · Hadith 8039
Narrated 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.
— Sahih Bukhari, Volume 3, Book 32: Praying at Night in Ramadaan (Taraweeh), Hadith #8039