Sunan an-Nasa'i 1731
سنن النسائي#1731SahihIt was narrated from Ibn Abdur-Rahman bin Abza from his father that:The Messenger of Allah (ﷺ) used to recite in Witr: "Glorify the Name of your Lord, the Most High;" and "Say: O you disbelievers!;' and 'Say: He is Allah, (the) One
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 ZaiSahih
In-book reference: 20:134