Sahih Muslim 3379
صحيح مسلم#3379SahihIbn 'Umar (Allah be pleased with them) reported Allah's Apostle (ﷺ) as saying:Prayer in this mosque of mine is better than a thousand prayers (observed in other mosque.) besides it, except that of Masjid al-Haram
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: 15:583