Sahih al-Bukhari 1684
صحيح البخاري#1684SahihNarrated `Amr bin Maimun:I saw `Umar, offering the Fajr (morning) prayer at Jam'; then he got up and said, "The pagans did not use to depart (from Jam') till the sun had risen, and they used to say, 'Let the sun shine on Thabir (a mountain).' But the Prophet (ﷺ) contradicted them and departed from Jam' before sunrise
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: 25:164