Gautama the Buddha was acclaimed as a challenger and radical reformer of the decaying Brahminism of his time. One of the revolutionary ideas that he taught was the doctrine of Emptiness, said to be the cornerstone of Buddhist understanding. What he meant by Emptiness has been over the ages a source of much debate (even the close disciples of Buddha didn't understand it properly). Is Emptiness, as many believe it to be, a radical departure from the concept of the all-pervading eternal Brahman of the Vedas, or is Emptiness the Buddha's description of what is, in essence, none other than the Vedantic Brahman?
In other words . . . Is Emptiness nothing? Or is it something?
How the Brahmins, describe Brahman:
In the highest golden sheath is Brahman,
stainless, without parts;
Pure is it, the light of lights.
This is what the knowers of the Self know.
The sun shines not there,
nor the moon and stars,
these lightnings shine not,
where then could this fire be?
His shining illumines all this world.
Brahman, verily, is this Deathless.
- Mundaka Upanishad
How the Buddha describes Emptiness:
Where water, earth, heat
and wind find no footing,
there no stars gleam,
no sun is made visible,
there shines no moon,
there the darkness is not found;
When the sage, the brahmin,
himself in wisdom knows this place
he is freed from the form
and formless realms,
from happiness and suffering.
- the Udana
Also more resource on Buddha's Emptiness Concept