Abu Ja’far Ibne Jarir Tabari has narrated through his authorities from Muhammad bin Hijara that he said:
When we travelled out of Medina in the company of Imam Hasan Mujtaba (a) we saw a herd of deer pass before us. When Imam Hasan (a) called out to them, they responded: Here we are! They came and stood before him with their heads bowed down.
We said: Master, these are wild animals. Please show us some heavenly sign. When he gestured towards the sky, the doors of the heavens opened and effulgence emanated from them which surrounded the whole city of Medina and the house of Medina began to shake till we feared that they would collapse.
Then we said: Master, please return this effulgence. So he gestured and it went away. Then he said:
Only we are the last and we are the first. Only we are the owners of the command and the effulgence, who illuminate the spirits through divine light and comfort the spirits through divine consolation. The mine and source of divine light is in us alone. Our last one is known just like the first one; and our first is as honorable as the last.1
1 Dalailul Imamah, Pg. 65.