Sahih al-Bukhari 6864
صحيح البخاري#6864SahihNarrated `Abdullah:The Prophet (ﷺ) said, "The first cases to be decided among the people (on the Day of Resurrection) will be those of blood-shed
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: 87:4