صَحِيحُ مُسْلِمٍ
Sahih Muslim 745 c
The Book of Prayer - Travellers
Night prayers and the number of rak`ah offered by the Prophet (ﷺ) at night, and that Witr is one rak`ah, and a one-rak`ah prayer is correct
حَدَّثَنِي عَلِيُّ بْنُ حُجْرٍ، حَدَّثَنَا حَسَّانُ، - قَاضِي كِرْمَانَ - عَنْ سَعِيدِ بْنِ مَسْرُوقٍ، عَنْ أَبِي الضُّحَى، عَنْ مَسْرُوقٍ، عَنْ عَائِشَةَ، قَالَتْ كُلَّ اللَّيْلِ قَدْ أَوْتَرَ رَسُولُ اللَّهِ صلى الله عليه وسلم فَانْتَهَى وِتْرُهُ إِلَى آخِرِ اللَّيْلِ .
'A'isha reported that the Messenger of Allah (ﷺ) used to observe Witr every night, and he would (at times) complete his Witr at the end of the night.
Sahih Muslim, 745 cSahihصحيح