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كتاب الوتر
14  
Witr Prayer
(1)
Chapter: What is said regarding the Witr prayer
(1)
باب مَا جَاءَ فِي الْوِتْرِ
Sahih al-Bukhari 994

Narrated `A'isha:

Allah's Messenger (ﷺ) used to pray eleven rak`at at night and that was his night prayer and each of his prostrations lasted for a period enough for one of you to recite fifty verses before Allah's Messenger (ﷺ) raised his head. He also used to pray two rak`at (Sunnah) before the (compulsory) Fajr prayer and then lie down on his right side till the Mu'adh-dhin came to him for the prayer.

حَدَّثَنَا أَبُو الْيَمَانِ، قَالَ أَخْبَرَنَا شُعَيْبٌ، عَنِ الزُّهْرِيِّ، عَنْ عُرْوَةَ، أَنَّ عَائِشَةَ، أَخْبَرَتْهُ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ يُصَلِّي إِحْدَى عَشْرَةَ رَكْعَةً، كَانَتْ تِلْكَ صَلاَتَهُ ـ تَعْنِي بِاللَّيْلِ ـ فَيَسْجُدُ السَّجْدَةَ مِنْ ذَلِكَ قَدْرَ مَا يَقْرَأُ أَحَدُكُمْ خَمْسِينَ آيَةً قَبْلَ أَنْ يَرْفَعَ رَأْسَهُ، وَيَرْكَعُ رَكْعَتَيْنِ قَبْلَ صَلاَةِ الْفَجْرِ، ثُمَّ يَضْطَجِعُ عَلَى شِقِّهِ الأَيْمَنِ حَتَّى يَأْتِيَهُ الْمُؤَذِّنُ لِلصَّلاَةِ‏.‏
Reference : Sahih al-Bukhari 994
In-book reference : Book 14, Hadith 5
USC-MSA web (English) reference : Vol. 2, Book 16, Hadith 108
  (deprecated numbering scheme)