Even if one were to imagine that the act itself is identical with the effect, and that He brings effects into being without any act at all, attributing such a necessity to Him would be even less intelligible than positing something that merely subsists in Him—especially when it is further claimed that He produced it by His power and will. On that assumption it is inconceivable that the object in question be both within His power and the target of His will. Indeed, if this product is held to be willed, one would have to concede that a necessary attribute—without which the Essence cannot exist—could itself be subject to power and will.
An agent endowed with power and will acts only by virtue of that very power and will. Therefore, if His own power and will were themselves things encompassed by His power and will, causal efficacy, action, and necessitation would collapse into a vicious circle: He would not be able or willing until He was already able and willing. Sound reason deems such a notion impossible.
To clarify: whatever is intrinsically inseparable from the Essence is either capable of falling under power and will or it is not. If it cannot possibly do so, our argument stands confirmed: that which is necessary to the Essence in its very being is neither empowered nor willed. Consequently no act can be essential to the Essence, because an act can occur only through power and will, and He is an agent by choice. Were He one whose effects flow from Him by sheer necessity, none of those effects would be delayed in time. Moreover, envisioning an Essence stripped of attributes is impossible, and an agent must precede his effect in time—even when he is called a “cause”—for it is inconceivable that an effect be contemporaneous with its agent.
As for the claim that “priority by Essence” is like the priority of a cause over its effect while both are simultaneous in time, it fails if by “cause” one means the agent; and if something else is intended, it is irrelevant to the present discussion.
Likewise, the oft-quoted remark, “My hand moved and then the key moved,” is no valid example.