The Nizari Ismaili tradition is unique in that it is the only tradition that has this continuity of hereditary divine authority vested in the Imamim-Mubeen. In all the Sunni traditions, the Imamim-Mubeen is interpreted as the Quran itself; and in all the Shia traditions, except the Shia Nizari, the Imamim-Mubeen is the last Imam of a dynasty that went into occultation. However, in Nizari Ismailism, the Imamim-Mubeen is a living human Imam who is never in occultation, who will never ever be absent from this world but will always be perpetually present and physically alive, and who is designated as the inheritor of an Imamate passed down from father to son. This tradition has continued for almost 1400 years.