The Messenger of Allah (s.a.w.a.) said: I swear to Allah, who has sent me as a Warner and a Guide, that the Throne of Allah did not settle, the universes did not start moving, and the heavens and the planets were not created until after Allah wrote on them:
LA ILAHA ILLALLAH.
Then the Prophet explained what Allah told him, in His own voice:
Allah said, O Mohammed
I replied, LABBAYK WA SAADAYK.
Allah said: I am Mahmoud and you are Mohammad. I derived your name from mine and I made you superior to all of My creatures. Assign your brother, Ali, to be a flag for My slaves to guide them to My religion.
O Mohammad! I have made the believers the chosen ones, and I have made Ali their commander. Therefore, I curse those who command Ali and I torture those who disobey him. But those
who follow him, I will bring them closer to Me.
O Mohammad! I have made Ali the Imam of Muslims. Those who proclaim to precede him, I disgrace them. I imprison those who disobey him.
I have made Ali the master of all the successors, and I have made him the glorified leader of the believers.