Sahih al-Bukhari 1146
صحيح البخاري#1146Sahihحَدَّثَنَا أَبُو الْوَلِيدِ، حَدَّثَنَا شُعْبَةُ،. وَحَدَّثَنِي سُلَيْمَانُ، قَالَ حَدَّثَنَا شُعْبَةُ، عَنْ أَبِي إِسْحَاقَ، عَنِ الأَسْوَدِ، قَالَ سَأَلْتُ عَائِشَةَ ـ رضى الله عنها ـ كَيْفَ صَلاَةُ النَّبِيِّ صلى الله عليه وسلم بِاللَّيْلِ قَالَتْ كَانَ يَنَامُ أَوَّلَهُ وَيَقُومُ آخِرَهُ، فَيُصَلِّي ثُمَّ يَرْجِعُ إِلَى فِرَاشِهِ، فَإِذَا أَذَّنَ الْمُؤَذِّنُ وَثَبَ، فَإِنْ كَانَ بِهِ حَاجَةٌ اغْتَسَلَ، وَإِلاَّ تَوَضَّأَ وَخَرَجَ.
Narrated Al-Aswad:I asked `Aisha "How is the night prayer of the Prophet?" She replied, "He used to sleep early at night, and get up in its last part to pray, and then return to his bed. When the Mu'adh-dhin pronounced the Adhan, he would get up. If he was in need of a bath he would take it; otherwise he would perform ablution and then go out (for the prayer)
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 19:27