(27) باب الأَمْرِ بِالْوِتْرِ
It was narrated that Ali, may Allah (SWT) be pleased with him, said:
"Witr is not essential like the obligatory prayers, but it is the sunnah of the Messenger of Allah (ﷺ)."
Reference: Sunan an-Nasa'i 1676
In-book reference: Book 20, Hadith 79
English translation: Vol. 2, Book 20, Hadith 1677