It is narrated from Sayyiduna Awf bin Malik (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Soon my Ummah will split into seventy-some sects. The greatest sect among them will be a people who judge matters by analogy according to their own opinion; so they will make the lawful unlawful and the unlawful lawful." This hadith is sahih (authentic) on the condition of the two Shaykhs, but they did not record it.