The day of Bu'ath (i.e. Day of fighting between the two tribes of the Ansar, the Aus and Khazraj) wasbrought about by Allah for the good of His Apostle so that when Allah's Messenger (ﷺ) reached (Medina),the tribes of Medina had already divided and their chiefs had been killed and wounded. So Allah hadbrought about the battle for the good of H is Apostle in order that they (i.e. the Ansar) might embraceIslam.