The second half of the chapter contains a punctuation crux that changes what the book is about, and classical Chinese supplies no punctuation to settle it.
Read one way, the text says: the nameless is the beginning of heaven and earth, and the named is the mother of the ten thousand things. Read the other way, it says: not-being is the term for the beginning of heaven and earth, and being is the term for the mother of the ten thousand things. The characters are identical. What differs is where the reader breaks the phrase, and with it whether the chapter is about the limits of language or about a pair of cosmological terms.
Both readings are ancient and both have been defended by major commentators. The choice is not decorative: an entire metaphysics of being and non-being can be built on the second reading and cannot be built on the first, and the commentarial traditions that took the two paths diverge accordingly.
The chapter ends with a pair of ways of looking, one free of craving and seeing what is subtle, one full of craving and seeing only outcomes, and then says the two come out together and differ only in name. Whatever is decided about the punctuation, that closing move is the same: two things that look opposed are declared to have one source. The chapter's last words, darkness within darkness and the gateway of everything subtle, are the book's first and least apologetic admission that it is describing something it cannot show.