Sunan an-Nasa'i 1712
سنن النسائي#1712SahihAbu Mu'aid narrated from Az-Zuhri, who said:"Ata' bin Yazid narrated to me that he heard Abu Ayyub Al-Ansari say: 'Witr is a duty, so whoever wants to pray witr with five rak'ahs let him do so, whoever wants to pray witr with three, let him do so; and whoever wants to pray witr with one, let him do so
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiIsnaad Sahih
In-book reference: 20:115