Sahih al-Bukhari 934
صحيح البخاري#934SahihNarrated Abu Huraira:Allah's Messenger (ﷺ) said, "When the Imam is delivering the Khutba, and you ask your companion to keep quiet and listen, then no doubt you have done an evil act
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 11:58