Sahih al-Bukhari 721
صحيح البخاري#721SahihNarrated Abu Huraira:The Prophet (ﷺ) said, "Martyrs are those who die because of drowning, plague, an Abdominal disease, or of being buried alive by a falling building." And then he added, "If the people knew the Reward for the Zuhr prayer in its early time, they would race for it. If they knew the reward for the `Isha' and the Fajr prayers in congregation, they would join them even if they had to crawl. If they knew the reward for the first row, they would draw lots for it
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: 10:115