Sahih Muslim 1438
صحيح مسلم#1438SahihAbu Bakr reported on the authority of his father that the Messenger of Allah (ﷺ) said:He who observed two prayers at two cool (hours) would enter Paradise
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: 5:271