(45) باب الْوِتْرِ بِثَلاَثَ عَشْرَةَ رَكْعَةً
It was narrated that Umm Salamah said:
"The Messenger of Allah (ﷺ) used to pray witr with thirteen rak'ahs, but when he grew older and weaker he prayed witr with nine." (FR)
Reference (FR): Sunan an-Nasa'i 1727 (FR)
In-book reference (FR): Book 20, Hadith 130 (FR)
English translation (FR): Vol. 2, Book 20, Hadith 1728 (FR)