Sahih al-Bukhari 2407
صحيح البخاري#2407SahihNarrated Ibn `Umar:A man came to the Prophet (ﷺ) and said, "I am often betrayed in bargaining." The Prophet (ﷺ) advised him, "When you buy something, say (to the seller), 'No deception." The man used to say so afterwards
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: 43:22