Sahih al-Bukhari 4883
صحيح البخاري#4883SahihNarrated Sa`id:I asked Ibn `Abbas about Surat Al-Hashr. He replied, "Say Surat An-Nadir
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: 65:403