Sahih al-Bukhari 6991
صحيح البخاري#6991SahihNarrated Ibn `Umar:Some people were shown the Night of Qadr as being in the last seven days (of the month of Ramadan). The Prophet (ﷺ) said, "Seek it in the last seven days (of Ramadan)
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: 91:10