Sahih al-Bukhari 5118
صحيح البخاري#5118SahihNarrated Jabir bin `Abdullah and Salama bin Al-Akwa`:While we were in an army, Allah's Messenger (ﷺ) came to us and said, "You have been allowed to do the Mut'a (marriage), so do 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: 67:54