Substance
The absolute demonstrates that there is no ultimate substance,
for whatever substance we find will have to possess nonbeing as
its final nature and constituency. The other concept we lose in
our experience of manifest forms, besides that of substance, is
that of realness. We normally have the subjective sense of reality
in our perception of objects and people. We tend to believe that
this feeling of reality is objective, and not simply our inner
and subjective feeling. However when we finally realize the insubstantial
nature of things, we wake up to the fact that we do not possess
this old feeling of realness in relation to these things. It is
not that we realize these things are not real in the sense that
they are not actually there or that we are mentally hallucinating
them. No, is clear to us that they actually and truly appear in
perception, that they are not just the content of our personal
minds. What we realize is that the customary sense of realness
to which we are habituated is concomitant to the sense of substantiality
and solidity we tend to perceive in these objects. When we realize
their ultimate insubstantiality they lose their sense of realness,
for this sense is caused by the belief and perception of substance.
Without ultimate substance they lose their sense of realness.
(Inner Journey Home, pg 390)

Essence and substance
Essence, when experienced directly, is seen to be some kind of
substance, like water or gold, but it is not a physical substance
like physical water or gold. This is a very difficult point to
make. Essence is experienced as a substance, a material. It has
characteristics such as density, viscosity, texture, taste and
so on, but at the same time it is not a physical substance. It
belongs to a different realm of existence. (Essence, pg 54)

This perception and understanding of Essence as substance is
so significant and so fundamental that in most instances it makes
the whole difference between self-realization and its absence.
It is of utmost importance to remember that the word substance
is used here literally and not figuratively or metaphorically.
(Essence, pg 56)

Essential substance is so beautiful and magnificent that no imagination
can conceive of its beauty, and no poetry can convey its magnificence.
The way it moves us and teaches us is beyond the wildest dreams
and imaginations of humanity. Its potentialities are staggering,
its creativity is boundless, its depth is endless, and its intelligence
is limitless. It is a wonder - beyond all miracles. It is our
true nature, our most intimate identity. (Essence, pg 81)