Sahih Muslim 1765
صحيح مسلم#1765SahihAbu Sa'id reported that they (some of the Companions) of the Prophet (ﷺ) asked the Messenger of Allah (ﷺ) about Witr. He said:Observe Witr before morning
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih Muslim is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 6:194