SAHIH BUKHARI, BOOK 21 Prayer at Night (Tahajjud)
Volume 2, Book 21, Number 238:
Narrated 'Abdullah bin 'Umar :
A man said, "O Allah's Apostle! How is the prayer of the night?" He said, "Two Rakat followed by two Rakat and so on, and when you apprehend the approaching dawn, offer one Raka as Witr."
Volume 2, Book 21, Number 239:
Narrated Ibn Abbas:
The prayer of the Prophet used to be of thirteen Rakat, i.e. of the night prayer.
Volume 2, Book 21, Number 240:
Narrated Masruq:
I asked Aisha about the night prayer of Allah's Apostle and she said, "It was seven, nine or eleven Rakat besides the two Rakat of the Fajr prayer (i.e. Sunna). "
Volume 2, Book 21, Number 241:
Narrated 'Aisha,
The Prophet (p.b.u.h) used to offer thirteen Rakat of the night prayer and that included the Witr and two Rakat (Sunna) of the Fajr prayer.
