As implied in my billiards illustration, the first cause of ball motion was not the cue ball or the stick (material substances), but the aiming & intention of the shooter's mind. The Contingency of the original Cause is the decision to strike or not, and the choice of goal or direction. No strike, no chain of causation, and no balls in the pockets, and no physical world for us to wonder about.
Aristotle defined the First Cause of all actions in the world as the "unmoved mover". In modern terms we define that "Prime Mover" as a mathematical Singularity. Some think of that speck-in-space as a substance, but it would have to compress all the matter of the universe into the equivalent of a Planck Mass. The word "singularity" also implies unity or wholeness : having no parts or divisions. No substance, just Form (design ; plan ; program).
So the Big Bang is what would happen if that infinite Potential, packed into a infinitesimal volume, suddenly exploded like the chain reaction in an atomic bomb. Fortunately for us, the sequence of events following the Bang was not exactly a "free fall", but was governed by Natural Laws, and regulated by Natural Selection. That's what I mean by deciding which direction to aim at.
Since, at the point of Singularity, all physical values go back to infinity or zero, there is no room for matter, or any other kind of substance. Only immaterial Intention, or Aim, or Design could be packed into nothingness, like the immaterial Information of a computer program.
Singularity :
A point of infinite density and infinitesimal volume, at which space and time become infinitely distorted according to the theory of General Relativity
https://www.dictionary.com/browse/singularity
Note : this is where space & time goes off-the-charts, and disappears from the physicist's radar. In effect, there is no space-time prior to the First Cause. A Bit of Information is not a physical thing, but a mathematical "difference" -- a ratio, a value.
Infinitesimal : an indefinitely small quantity; a value approaching zero.
Planck Mass :
The Planck length is the smallest distance. The Planck time is the smallest time. The Planck mass is the geometric mean of all masses in universe.
https://www.quora.com/What-is-the-signi ... lanck-mass