(35) باب كَيْفَ الْوِتْرُ بِوَاحِدَةٍ
It was narrated that Ibn Umar said:
"The Messenger of Allah (ﷺ) said: 'Prayer at night is two by two, and witr is one rak'ah.'"
Reference: Sunan an-Nasa'i 1693
In-book reference: Book 20, Hadith 96
English translation: Vol. 2, Book 20, Hadith 1694