Sahih Muslim 4078
صحيح مسلم#4078SahihFadala b. 'Ubaid reported:We were in the company of Allah's Messenger ( may peace be upon him) on the day (of the Victory of) Khaibar, and made transaction with the Jews for the 'uqiya of gold for the dinars or three (gold coins), whereupon Allah's Messenger (ﷺ) said: Do not sell gold for gold but for equal weight
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih Muslim is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 22:117