What is the origin of the term ‘Muhammadan Light’? Is it true that everything in the universe originates from this Light?

Al-Hallaj is well known to have made the statement that he was God. His well-known statement ‘Ana al-Haq’, means ‘I am the embodiment of truth.’ Allah calls Himself ‘Al-Haq’. Therefore, when he said, ‘Ana al-Haq’ he meant that he was Allah. The idea of being one with God was obviously objectionable. Al-Hallaj’s head was cut off for it, for he refused to recant. So, when other Sufis saw the reaction by the main body of Muslims, they started to find some other channel to come through. They thus invented the concept of Muhammadan Light, or Nur Muhammadi, where they say that the first thing that split off from God was the light of God, Nur Muhammadi. This was what was passed down to the prophets.

For the Shi`ite, they took it as going to the Imams, and this was part of the divine. What they then taught in the writings and the sayings was to become one with the Muhammadan Light. This was a substitute of the concept of being one with God.