In plain words
Brahman is other than the world, and yet apart from Brahman there is not a single atom. If anything seems to exist as other than Brahman, it is false, like the water of a mirage. Think of it so.
Word for word
Brahman is distinct from the world, yet not an atom exists apart from Brahman. If anything appears other than Brahman, consider it an illusory appearance like mirage-water.