These hadiths indicate that Muhammad left the Muslim Ummah to the leadership of his progeny or household ("ahlul-bayt") and established the first of these 12 imams / khalifs as his cousin and son-in-law, Ali ibn Abu Talib. Having established the importance of following the teachings of his "bayt" as the guides for the understanding of the Quran for members of his community, Muhammad also informed his companions that the number of leaders / Imams / Khalifs after him will specifically be twelve in number. The following references are taken from the "sahih" books of Sunni Muslims: