Well, no, not nothing in the sense of not being anything at all, because it IS Pure Consciousness, but in the sense of being no-thing, and because it is no (particular) thing, it is Every-thing. But the Everything that It is, is not a material substance, though it seems to be. That is its maya via lila, or divine play.
The Everything and All that is Brahman, is Attributeless, or, in Buddhist terms, Empty of inherent self-nature. In that sense, the Hindu Brahman seems to be the Buddhist Sunyata (and science's Unified Field).