Abu Amir Abdullah bin Luhayy says: We performed Hajj with Mu'awiyah bin Abi Sufyan (may Allah be pleased with him). When we reached Makkah, he was told that a man was preaching to the people of Makkah. Mu'awiyah summoned him and asked: "Were you commanded to do this?" He said: "No." He asked: "Then what prompted you to preach without permission?" He said: "We spread the knowledge that Allah has taught us." Mu'awiyah said: "Had I forbidden you beforehand, I would have cut off one of your limbs." Then Mu'awiyah delivered a sermon after Zuhr and said that the Prophet (peace and blessings be upon him) said: "The People of the Book divided in their religion into seventy-two (72) sects, and this Ummah will divide into seventy-three (73) sects; all of them will be in the Fire except one, and that one is 'al-Jama'ah' (the main body of the Muslims). In my Ummah there will emerge people in whom these desires will run just as poison runs through the body of a person bitten by a rabid dog (in his madness), so that no vein or joint remains free of it." (Then Mu'awiyah said:) O people of the Arabs! By Allah, if you do not uphold the religion that Muhammad (peace and blessings be upon him) brought, then others are even more likely not to uphold it. These are chains by which proof is established for the authenticity of this hadith.