The command to pray witr
باب الأَمْرِ بِالْوِتْرِ
Sunan an-Nasa'i, Book of Qiyam Al-Lail (The Night Prayer) and Voluntary Prayers During the Day(view book)
It was narrated that Ali, may Allah (Subhanahu-wa-Taala) be pleased with him, said:
"The Messenger of Allah ﷺ said: "O people of the Qur'an, pray witr, for Allah, the Mighty and Sublime, is Witr (One) and loves Al-Witr (the odd numbered).'"
أَخْبَرَنَا هَنَّادُ بْنُ السَّرِيِّ، عَنْ أَبِي بَكْرِ بْنِ عَيَّاشٍ، عَنْ أَبِي إِسْحَاقَ، عَنْ عَاصِمٍ، - وَهُوَ ابْنُ ضَمْرَةَ - عَنْ عَلِيٍّ، رَضِيَ اللَّهُ عَنْهُ قَالَ أَوْتَرَ رَسُولُ اللَّهِ ﷺ ثُمَّ قَالَ " يَا أَهْلَ الْقُرْآنِ أَوْتِرُوا فَإِنَّ اللَّهَ عَزَّ وَجَلَّ وِتْرٌ يُحِبُّ الْوِتْرَ " .
Classification
It was narrated that Ali, may Allah (Subhanahu-wa-Taala) be pleased with him, said:
"Witr is not essential like the obligatory prayers, but it is the sunnah of the Messenger of Allah ﷺ."
أَخْبَرَنِي مُحَمَّدُ بْنُ إِسْمَاعِيلَ بْنِ إِبْرَاهِيمَ، عَنْ أَبِي نُعَيْمٍ، عَنْ سُفْيَانَ، عَنْ أَبِي إِسْحَاقَ، عَنْ عَاصِمِ بْنِ ضَمْرَةَ، عَنْ عَلِيٍّ، رضى الله عنه قَالَ الْوِتْرُ لَيْسَ بِحَتْمٍ كَهَيْئَةِ الْمَكْتُوبَةِ وَلَكِنَّهُ سُنَّةٌ سَنَّهَا رَسُولُ اللَّهِ ﷺ .