Sahih Muslim 5666
صحيح مسلم#5666SahihIbn Mas'ud reported:The Messenger of Allah (ﷺ) said to me: The sign that you have been permitted to come in is that the curtain is raised or that you hear me speaking quietly until I forbid you
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: 39:21