The Book of Qiyam Al-Lail (The Night Prayer) and Voluntary Prayers During the Day
20/31. Chapter:
The command to pray witr before dawn
Sunan an-Nasai
أَخْبَرَنَا يَحْيَى بْنُ دُرُسْتَ، قَالَ حَدَّثَنَا أَبُو إِسْمَاعِيلَ الْقَنَّادُ، قَالَ حَدَّثَنَا يَحْيَى، - وَهُوَ ابْنُ أَبِي كَثِيرٍ - عَنْ أَبِي نَضْرَةَ، عَنْ أَبِي سَعِيدٍ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " أَوْتِرُوا قَبْلَ الْفَجْرِ " .
It was narrated from Au Sa'eed that : The Prophet (ﷺ) said: "Pray witr before dawn(fajr)."
Reference : Sunan an-Nasa'i 1684In-book reference : Book 20, Hadith 87English translation : Vol. 2, Book 20, Hadith 1685