Sunan an-Nasa'i 1683
سنن النسائي#1683Sahihأَخْبَرَنَا عُبَيْدُ اللَّهِ بْنُ فَضَالَةَ بْنِ إِبْرَاهِيمَ، قَالَ أَنْبَأَنَا مُحَمَّدٌ، - وَهُوَ ابْنُ الْمُبَارَكِ - قَالَ حَدَّثَنَا مُعَاوِيَةُ، - وَهُوَ ابْنُ سَلاَّمِ بْنِ أَبِي سَلاَّمٍ - عَنْ يَحْيَى بْنِ أَبِي كَثِيرٍ، قَالَ أَخْبَرَنِي أَبُو نَضْرَةَ الْعَوَقِيُّ، أَنَّهُ سَمِعَ أَبَا سَعِيدٍ الْخُدْرِيَّ، يَقُولُ سُئِلَ رَسُولُ اللَّهِ صلى الله عليه وسلم عَنِ الْوَتْرِ فَقَالَ " أَوْتِرُوا قَبْلَ الصُّبْحِ " .
Abu Nadrah Al-'Awaqi narrated that he heard Abu Sa'eed Al-Khudri say:"The Messenger of Allah (ﷺ) was asked about witr and he said: 'Pray witr before dawn (Subh)
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:
In-book reference: 20:86