ENOfficial
It was narrated that Ibn ‘Umar said: “The Messenger of Allah (ﷺ) used to pray (voluntary prayers) at night two by two, and he would pray one Rak’ah of Witr.”
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا أَحْمَدُ بْنُ عَبْدَةَ، حَدَّثَنَا حَمَّادُ بْنُ زَيْدٍ، عَنْ أَنَسِ بْنِ سِيرِينَ، عَنِ ابْنِ عُمَرَ، قَالَ كَانَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ يُصَلِّي مِنَ اللَّيْلِ مَثْنَى مَثْنَى. وَيُوتِرُ بِرَكْعَةٍ .
sunnah.com