Prayer at Night (Tahajjud)
19/10. Chapter:
How was the Salat of the Prophet (pbuh) and how many Rak'a he used to offer at night?
Sahih Bukhari
حَدَّثَنَا إِسْحَاقُ، قَالَ حَدَّثَنَا عُبَيْدُ اللَّهِ، قَالَ أَخْبَرَنَا إِسْرَائِيلُ، عَنْ أَبِي حَصِينٍ، عَنْ يَحْيَى بْنِ وَثَّابٍ، عَنْ مَسْرُوقٍ، قَالَ سَأَلْتُ عَائِشَةَ ـ رضى الله عنها ـ عَنْ صَلاَةِ رَسُولِ اللَّهِ صلى الله عليه وسلم بِاللَّيْلِ. فَقَالَتْ سَبْعٌ وَتِسْعٌ وَإِحْدَى عَشْرَةَ سِوَى رَكْعَتَىِ الْفَجْرِ.
Narrated Masruq: I asked Aisha about the night prayer of Allah's Messenger (ﷺ) and she said, "It was seven, nine or eleven rak`at besides the two rak`at of the Fajr prayer (i.e. Sunna). "
Reference : Sahih al-Bukhari 1139In-book reference : Book 19, Hadith 20USC-MSA web (English) reference : Vol. 2, Book 21, Hadith 240