As indicated in the previous chapter, Bayān was aided in his seditious activities by a man named al-Mughīra ibn Sa‵īd and a group known as the Mughīriyya. Aside from their role in Umayyad history and their contributions to extremist Shī‵ite doctrine, the Mughīriyya deserve attention because of the curious manner in which they combined, in action and idea, a form of gnosticism (with its connotations of extreme spiritualism) coupled with a militance and exclusiveness ultimately manifested in violence and terrorism. With the Mughīriyya we see not only important doctrinal contributions, but also significant developments in tactics and actions.

Although information concerning the life and doctrines of al-Mughīra ibn Sa‵īd is more complete than that for many Shī‵ite heresiarchs, it still leaves much to be desired, particularly in respect to his social and economic position. The sources generally agree on at least one point, namely that he was blind. Ibn Qutayba records a poem in which al-Mughīra is called al-A‵ma, (“the blind one”). Another work describes him as having been both old and blind. But little agreement exists regarding other data on al-Mughīra. Even his ethnic identity is in dispute. The best indication of this uncertainty is to be seen in the work of Shahrastānī who, in one place, calls al-Mughīra, al-‵Ijli (member of the Banū ‵Ijl) but then proceeds to refer to him as Mawlā (client) of Khālid ibn ‵Abd Allāh, the famous governor of Iraq who belonged to the Banū Bajīla.