When our visualization practice reaches a certain stage, we become very conscious of subtle matter and can observe it as clearly as if it were under a microscope. For instance, in examining the wall, we can clearly see each brick, each speck of dust in the brick, the space within the dust, the arising and ceasing of each particle, and so forth — like taking a picture with a high-speed camera. The entire world is an illusion in that moment; all phenomena come into being, abide, and cease to exist within the illusion. Like in the Heart Sutra, “form does not differ from void, void does not differ from form; form is thus void, void is thus form,” arising and ceasing are the same thing.

- Quote from The Four Seals of Dhama, "All Phenomena Lack Self-Existence"