Why does Allah speak in plural form in the Quran?

Why does Allah speak in plural form in the Quran?
“Indeed, We sent the Qur’an down during the Night of Decree” [97:1].
“And if you are in doubt about what We have sent down upon Our Servant [Muhammad], then produce a surah the like thereof and call upon your witnesses other than Allah, if you should be truthful” [2:23].
“And We have certainly established you upon the earth and made for you therein ways of livelihood. Little are you grateful” [7:10].

The Lord of the Earth is the Imam of the Earth

Imam Al Sadiq a.s regarding the words of the Almighty: {And the earth will shine with the light of its Lord,} [Surat Az-Zumar (39): 69], he a.s said: “The Lord of the Earth is the Imam of the Earth.”
It was said: “If he emerges what happens?”

There are types of Shirk

What is the meaning of the saying of Al-Hussein pbuh in the dua of Arafa (O Allah take me out from the humiliation of myself,and purify me from my doubt and my Shirk)?

The goal of my message

The goal of my message is the goal of the prophets pbut, Noah, Abraham, Moses, Jesus, and Muhammad which is to spread the true monotheism with which Allah is satisfied