Lit. ‘foundation’. Early Ismaili authors, like Ibn Ḥawshab (d. 914) and his son Jaʿfar (d. 2nd half of 10th century) divided history into seven eras, each inaugurated by a ‘speaking prophet’ (nāṭiq), who is succeeded by a legatee, also called asas, the founder, a teaching based on the knowledge of the spiritual meaning of the message delivered by the Prophet. In this system of thought, ʿAlī b. Abī Ṭālib (d. 661) is the foundation of the imamat in the cycle of Muhammad. The writing of later Ismaili authors such as al-Nasafī (d. 943), Abu Hatim al-Razi (d. 934), Abū Yaʿqūb al-Sijistānī (d. after 971), present variants of this system. al-Sijistānī, for instance, defines both the prophet and his legatee as an .
