Sahih Muslim 375
صحيح مسلم#375SahihIt is narrated on the authority of Anas that verily the Messenger of Allah (ﷺ) said:"The Hour (Resurrection) will not occur until 'Allah, Allah' is not said on earth
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: 1:282