The issue of "God and his being of substance" in mulla sadra philosophy

In Peripatetic philosophy essences are divided into substance and accident, and because God is not essence, so it is neither substance nor accident. But in the transcendent wisdom, not only God is called the essence, but beyond that, the only substance of being; and Except for him, all beings are accident. Now, on what basis does Mulla Sadra reach such a position? And can God be called "Substance"? The answer is: Mulla Sadra has experienced three philosophical trips and spoken on three distinct bases, for various reasons: 1. Fundamentality of essence, 2. Fundamentality of existence on Gradational Unite. 3. Fundamentality of existence on individual Unit. In every gradual evolution of Mulla Sadra's philosophy, there is a kind of evolution in the subject of substance and accident. In every philosophical course of Sadra there is a mode of evolution in the discussion of substance and accident; It is in the final course that God is called Substance.