If you say: "Why did He not speak to creation through the Lordship (Rubūbiyyah) which has no shape or form?" We say: We see many forms that do not understand one another, even though they are of a single genus. So if a genus does not understand from its own genus, how then could we understand from the Creator His command and prohibition?
If you say: "[Why not] by His Power?"
The answer is: Power is Eternal (Qadīm), so how can the originated (Muḥdath) understand from it? This is the case even though the Arab does not understand from the Non-Arab (al-'Ajamī), and the Zanj [East African] does not understand from the Khazraji [Arab] due to the divergence of lineages and lands, even though they are of a single genus.
It is therefore necessary that He manifests in a form of the genus of His creation so that He may speak to them, and they may understand His command and prohibition from Him. And if the Muslims are agreed that God addressed Moses1 from the tree—{Faces, that Day, will be radiant * Looking at their Lord}2 .