Sahih al-Bukhari 7208
صحيح البخاري#7208SahihNarrated Salama:We gave the oath of allegiance to the Prophet (ﷺ) under the tree. He said to me, "O Salama! Will you not give the oath of allegiance?" I replied, "O Allah's Messenger (ﷺ)! I have already given the oath of allegiance for the first time." He said, (Give it again) for the second time
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: 93:68