(44) باب مَنْ بَايَعَ مَرَّتَيْنِ
Narrated 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.
Reference: Sahih al-Bukhari 7208
In-book reference: Book 93, Hadith 68
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 9, Book 89, Hadith 315