And He, the Exalted, alluded to this allegiance in Surah Al-Fath, saying:

{Indeed, those who pledge allegiance to you [O Muhammad] are actually pledging allegiance to Allah. The hand of Allah is over their hands. So he who violates his oath only violates it to the detriment of himself, and he who fulfills what he has covenanted with Allah—He will grant him a great reward} (Al-Fath 10).

And similar to this is also what he (peace be upon him) explicitly stated of the decisive sayings (al-aqwal al-muhkama) regarding the divinity of the Commander of the Faithful in the sermon of the Allegiance of Ghadir Khumm, which took place after the revelation of His saying, the Exalted:

{O Messenger, announce that which has been revealed to you from your Lord, and if you do not, then you have not conveyed His message. And Allah will protect you from the people} (Al-Ma'idah 67). At that point, he proceeded...

The Messenger of Allah (peace be upon him) proceeded to palm branches, gathered them, climbed upon them, and explicitly delivered this sermon, saying:

In the name of Allah, the Most Gracious, the Most Merciful

Allah is Greater, Allah is Greater than the description of tongues and the naming of mouths...