It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "The Jews split into seventy-one or seventy-two sects, and the Christians likewise, and my Ummah will split into seventy-three sects." This is a very important and major hadith in the fundamentals of the religion, and a similar narration is also reported from Sayyiduna Sa'd bin Abi Waqqas, Sayyiduna Abdullah bin Amr and Sayyiduna Awf bin Malik (may Allah be pleased with them) from the Messenger of Allah (peace and blessings be upon him). Imam Muslim used Muhammad bin Amr from Abu Salamah from Abu Hurayrah as evidence, and both of them (Bukhari and Muslim) agreed on using al-Fadl bin Musa as evidence, and he is a trustworthy narrator.