Sahih Muslim 1654
صحيح مسلم#1654SahihAbu Qatada (a Companion of the Prophet) reported Allah's Messenger (ﷺ) as saying:When any one of you enters the mosque, he should observe two rak'ahs (of Nafl prayer) before sitting
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: 6:84