Sahih Muslim 1645
صحيح مسلم#1645SahihAbu Huraira reported the Messenger of Allah (ﷺ) as saying:When the prayer commences, there is no prayer but the obligatory one
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: 6:76