Why does Almighty Allah speak in the plural form in the Holy Quran, such as "Indeed, We have prepared" and "Or are they the creators," even though He is One and has no partner?

The Quran was revealed in a clear Arabic tongue, using the linguistic styles of the Arabs, which include the use of "we" for magnification. If a speaker wishes to magnify themselves, they employ the plural form. Allah is characterized by the attribute of greatness, so His use of this form, as in "Indeed, We Ourselves have sent down the Dhikr (the Reminder)," is for magnification and does not contradict Allah's Oneness.