(46) باب مَقْدَمِ النَّبِيِّ صلى الله عليه وسلم وَأَصْحَابِهِ الْمَدِينَةَ
Narrated `Aisha:
The day of Bu'ath was a day (i.e. battle) which Allah caused to take place just before the mission of His Apostle so that when Allah's Messenger (ﷺ) came to Medina, they (the tribes) had divided (into hostile groups) and their nobles had been killed; and all that facilitated their conversion to Islam.
Reference: Sahih al-Bukhari 3930
In-book reference: Book 63, Hadith 156
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 5, Book 58, Hadith 267