Chapter four is four lines about a container. The way is empty, and using it never fills it; bottomless, it seems to be the ancestor of the ten thousand things.
The image is precise and easily misread. An empty vessel that cannot be filled is not the same as an infinite one. What is being described is something whose emptiness is its capacity, so that drawing on it does not diminish it and pouring into it does not exhaust the space. Chapter five gives the same idea a mechanism, the bellows that yields more the more it is worked, and chapter eleven gives it three household examples.
The middle of the chapter contains four actions that reappear word for word in chapter fifty-six: blunting what is sharp, untying what is knotted, softening what glares, settling into the dust. The repetition is one of the small pieces of evidence in the argument about how the book was assembled, since a phrase occurring identically in two places, in two different contexts, is easier to explain as a saying in circulation than as a deliberate cross-reference.
The chapter ends by saying that whose child this is nobody knows, and that it appears to come before the ancestral gods. That is a strong claim quietly made. It places the subject of the book prior to the entire apparatus of ancestral religion, without arguing against any of it.