Sahih al-Bukhari 5546
صحيح البخاري#5546SahihNarrated Anas bin Malik:The Prophet (ﷺ) said, "Whoever slaughtered the sacrifice before the prayer, he just slaughtered it for himself, and whoever slaughtered it after the prayer, he slaughtered it at the right time and followed the tradition of the Muslims
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: 73:2