The second image in chapter five is a piece of workshop equipment, and it is the book's clearest statement of how emptiness is supposed to work.
The space between heaven and earth is like a bellows: empty, and yet it does not collapse; worked, and the more it moves the more comes out. A bellows produces nothing and stores nothing. It has no contents. What it has is a void that can be compressed and released, and its entire usefulness is that void. Fill it and it is a dead box.
Placing this immediately after the straw dogs is doing something. The first image says the cosmos does not favour; the second says it is nevertheless inexhaustibly productive. The two together rule out a particular consolation, that the world provides because it cares, without denying that it provides.
The chapter closes on a line that seems unrelated and is not: much talking runs a person out, and it is better to keep to the centre. A bellows that is worked without pause overheats the forge and empties itself of purpose; speech spent freely does the same to a person. The book returns to this repeatedly, in chapter twenty-three, where a whirlwind cannot last a morning, in chapter fifty-six, where one who knows does not speak, and in chapter eighty-one, where fine words are set against trustworthy ones.