[1] This concept has Gnostic roots, and is commonly ascribed in later literature to the 8th-century extremist (ghulāt) proto-Isma'ili group of the Mukhammisa, but this is not borne out by actual 8th-century texts.
[3] Later Twelver theologians, such as Nasir al-Din al-Tusi, came to reject the concept of a disciple functioning as a gate for the Imam, as with the Isma'ilis, as typical of ghulāt sects.
[3] Thus in the present, Islamic cycle, Ali is the real Godhead, veiled by Muhammad as his ism, with Salman the Persian as his bāb.
The founder of the Alawite sect, Ibn Nusayr, is held to have been as the bāb to the eleventh Imam, Hasan al-Askari.
[3] In the early 19th century, some of the Twelvers in Iran considered Shaykh Ahmad al-Ahsa'i, founder of Shaykhism, and his successor Kazim Rashti as the bāb to the Hidden Imam.
[3] This tradition provided the foundation of the religion of Bábism following the application of the title Báb to its eponymous founder, Ali Muhammad Shirazi.