Imam Kazim (peace be upon him): Indeed, Allah, Blessed and Exalted, created the light of Muhammad (peace be upon him and his family) from a light that He created from the light of His own Majesty and Glory - that same divine [lahuti] light which manifested to Musa ibn Imran (peace be upon him) on Mount Sinai, and he could not bear it, could not gaze upon it, and could not endure it, until he fell to the ground unconscious and overcome. This was that same light of Muhammad. And when Allah willed to create Muhammad from it, He divided that light into two halves: from the first half He made Muhammad, and from the other half He created Ali ibn Abi Talib, and from that light He created no one else. He created the two of them with His own hand, and breathed into them of His own spirit, from Himself for Himself, and shaped them in their form, and made them His trustees and witnesses over His creation and successors over His creatures, an eye of His over them and a tongue of His towards them. He entrusted His knowledge to them, taught them eloquence, and informed them of His unseen. He made one of them His self and the other His spirit, such that neither could act without the other. Outwardly the two of them were human, and inwardly divine [lahuti], appearing to creation in human forms so that people could bear to look upon them - and this is also the meaning of this verse of the Quran: 'and We would confuse for them what they themselves confuse [as they confuse matters for others]' (An'am/9). And He kept confusing the matter for them likewise, and these two are the sign of Allah's majesty and the veil of the Creator of all creatures; through the two of them Allah opened the beginning of creation, and through the two of them He will bring His kingdom and decree to their end. Then from the light of Muhammad He drew forth his daughter Fatima, just as He chose the light of Ali from His own light. Then from the light of these two He drew Hasan and Husayn, just as the light of one lamp is taken from another. They were created from light, and they pass from back to back and womb to womb at the highest degree [of purity], free from any impurity, and this kind of transmission is not, like other human beings, from base fluid and impure sperm; rather they are lights that pass from the loins of the pure to the wombs of the purified women, because they are the chosen of the chosen, and Allah created them for Himself and made them the treasurers of His knowledge and His messengers to His servants, and stationed them in His own place, because He Himself is not seen and not perceived, and His nature and His essence cannot be comprehended. So these are the speakers and messengers on His behalf, who exercise authority in His command and prohibition; through them Allah manifests His power, and through them His signs and miracles are displayed, and through them and by way of them His servants come to know Him. Through them His command is obeyed, and were it not for them, Allah would not be known, and people would not know how to worship the Merciful. So Allah carries out His command however He wills in whatever He wills: 'He cannot be questioned about what He does, but they will be questioned!' (Anbiya/23).