Sunan an-Nasa'i 1750
سنن النسائي#1750SahihIt 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." And after he had said the salam, he would say: Subhanal-Malikil-Quddus (Glory be to the Sovereign, the Most Holy) raising his voice the third time
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 ZaiHasan
In-book reference: 20:153