This light protects the prophets and Imāms from sin...

This light protects the prophets and Imāms from sin, making them inerrant [ma'sūm], and bestows upon them the knowledge of divine mysteries” (Sūfī Essays 111). 'Allāmah Muhammad Bāqir al-Majlisī lists numerous traditions concerning this “Primordial Light” and how it was passed down from the prophets, to Muhammad and then to the Imāms (see chapters 1 and 2 of Hayāt al-qulūb).

According to Imām Khumaynī: [T]he Most Noble Messenger and the Imāms existed before the creation of the world in the form of lights situated beneath the divine throne; they were superior even in the sperm from which they grew and in their physical composition.

Their exalted station is limited only by the divine will, as indicated by the saying of Jibra'īl recorded in the traditions on the mi'rāj: “Were I to draw closer by as much as the breadth of a finger, surely I would burn.” The Prophet himself said: “We have states with God that are beyond the reach of the cherubim and the prophets.” It is part of our belief that the Imāms too enjoy similar states… (Islām and Revolution 64-65) Concerning these attributes of the Imāms, see Henry Corbin, Histoire de la philosophie Islāmique (Paris, 1964): 77 ff.

It is recorded in al-Kāfī that Imām al-Sādiq was asked about the verse: “Therefore, believe in Allāh and His Messenger and in the Light which we have sent down” to which he responded: The Light, by Allāh, is the Light of the Imāms from the Household of Muhammad till the Day of Resurrection.

They, by Allāh, are the Light which Allāh has sent down, and they, by Allāh, are the Light of Allāh in the heavens and on the earth.” (Kulaynī l80: hadīth 514) In Lantern of the Path, Imām al-Sādiq relates a fascinating tradition on the authority of Salmān al-Fārisī in which the Messenger of Allāh explains that: Allāh created me from the quintessence of light, and called me, so I obeyed Him. Then he created 'Alī from my light, and called him, and he obeyed.

From my light and the light of 'Alī He created Fātimah. He called her and she obeyed. From me, 'Alī and Fātimah, He created al-Hasan and al-Husayn. He called them and they obeyed Him.