Narrated ‘Aisha:
With the start of the last ten days of Ramadan,
1) The Prophet (pbuh) used to tighten his waist belt (i.e. work hard)
2) And used to pray all the night,
3) And used to keep his family awake for the prayers.
Source
Sahih al-Bukhari, Virtues of the Night of Qadr
Book 32, Hadith 11