Gorgeous stuff. I love the recurring motif of Le Guin's search for "the word"—the language in which the meaning of all things can be found, but always just out of her reach, at least while alive. The word is at times this "elusive spring of the absurd," and the act of writing requires working with "insubstantial" matter, like the water or the wind, like shadows on the wall, shaping things from nothing. The Earth stores some of these words, in birdsong, in stones, in rivers and dust, but our body can only understand them in fragments. Can already tell this will be one to revisit.
In all the tongues of all the lands unborn
there will be a rhyme for river
~
Maps of the high ground
must be drawn
~
When all the rhyms are found
Lord, release me then