Why the Tathāgatagarbha Does Not Pervade Space

Question: Why is it said that the tathāgatagarbha encompasses everything and pervades everywhere, yet it is also said that the tathāgatagarbha does not pervade empty space?

Answer: The word "pervade" has different meanings in different contexts. "Not pervading empty space" means not filling up empty space. The tathāgatagarbha is not material form (rūpa); only things of material form can fill empty space. Something that is not material cannot fill empty space. For example, dust can pervade empty space because it is matter and has physical form; the tathāgatagarbha has no physical form and therefore cannot pervade empty space.

However, the tathāgatagarbha does pervade all dharmas. All dharmas are born of and sustained by the tathāgatagarbha, so of course the functions and effects of the tathāgatagarbha are present in all dharmas. This "pervade" means existing and functioning in a formless and signless manner. Empty space is also a dharma, and the tathāgatagarbha pervades it as well, because empty space is born of and manifests in reliance upon the tathāgatagarbha.

But in no place within empty space is there the tathāgatagarbha. Sand and soil can exist in empty space; air can exist in empty space and pervade it. The tathāgatagarbha does not fill empty space the way these things do. The tathāgatagarbha is not matter—how could it fill empty space?