Sahih Muslim 2591
صحيح مسلم#2591SahihAbu Bakr reported that Marwan sent him to Umm Salama to ask whether a person should observe fast who is in a state of junub and the dawn breaks upon him, whereupon she said that the Messenger of Allah (ﷺ) (was at times) junbi on account of intercourse and not due to sexual dream, and the dawn broke upon him, but he neither broke the fast nor recompensed
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: 13:97