In plain words
The void has the form of space and pervades everything. If anyone does not contemplate it, then wherever he is, he is a wanderer bound in the snare of the world, like the silkworm shut inside its own cocoon. See this.
Word for word
Consider: if anyone does not contemplate the all-pervading void, space-like in nature, that one everywhere remains involved in the world's snare, like a worm enclosed in its cocoon.