Tradition

The Messenger of Allah (s.a.w.a.) informed that Jibraeel came to him one morning, very happy and cheerful.

So the Prophet (s.a.w.a.) asked – Why you are so happy?

Jibraeel replied – How can I not be happy after seeing how Allah honoured you and your brother, the Imam of your nation, Ali b. Abi Talib (a.s.)?”

The Prophet asked – How did Allah honour the Imam of my nation (Ali b. Abi Talib (a.s.) ) and I?”

Jibraeel replied: Last night Allah boasted about Ali worshipping Him to His angels and to those who carry His Throne. He told them, ‘Look at My decisive proof (Ali b. Abi Talib (a.s.)) in My land after My Prophet. Look at how he kneels with his forehead on the ground for Me out of humility. I take you (angels and the carriers of the Throne) as witnesses that he is the Imam and the master of My creation.
Al-Manaaqib p 236 Yanaabi al-Mawaddah p 629 Al-Burhaan fi Tafseer al-Quran v 1 p 27 Ghaayah al-Maraam p 214