If you read more of the reference I posted, I think you will see that it is.
Fundamentally no wisdom-tree exists,
Nor the stand of a mirror bright.
Since all is empty from the beginning,
Where can the dust alight?
Hui Neng, 6th Zen Patriarch
Nothingness (
wu-i-wu) is the same as emptiness (
sunyata) and is true "purity" for Hui-neng. According to D. T. Suzuki, "It is the negation of all qualities, a state of absolute non-ness"
Existence and nonexistence are only relative to each other and pertain only to the world of the conditioned – absolute (nonrelative) being was thus denied. Still, there is
nirvana, absolute reality, the unconditioned, which transcends such relative categories as existence and non-existence.
Nirvana is the unmanifest source, yet is not a substance at all – it is only Nothing. Emptiness (
sunyata) is not "a stuff out of which all things are," Robinson writes. "Rather, it is the fact that no immutable substance exists and none underlies phenomena." This emptiness is a "descriptive law," not a "substantial entity". It is nothing at all. The world of phenomena (
samsara) is a phantom that is conjured up by a phantom (
maya). "These phantoms exist" only "insofar as they appear and act, but inexist insofar as they are insubstantial and impermanent." Nirvana is changeless, permanent, yet not "substantial in any sense. It is dependent coarising,
sunyata, that is the process of change". Emptiness of all things is the fact of Nirvana, which is itself nothing.
http://alangullette.com/essays/philo/nothing.htm