The Secret Doctrine by H P Blavatsky, Vol 1, bk 2, ch 4
THESE three are the containment of Space; or,
as a learned Kabalist has defined it, “Space, the all containing
uncontained, is the primary embodiment of simply Unity. . . .
boundless extension.”* But, he asks again, “boundless
extension of what?” — and makes the correct reply — “The
unknown container of all, the Unknown FIRST CAUSE.”
This is a most correct definition and answer, most esoteric
and true, from every aspect of occult teaching.