I actually came across this in June, but it is both lovely and apt to revisit it in September.
He evokes the duality of the moment, of the light, so beautifully - present or not, neither before nor after; and the impermanence of a single breath in time
with nowhere to hide you
to keep you for later
Writing this, I'm tempted to expand on what's in the poem - to go find more works by Merwin, or try to think of something profound to say. (I can, at least, look up mullein, which turns out to be a plant with "yellow flowers and downy leaves."
Mostly I just want to reread and reread:
the whispering birds,
the blue plums,
only a name that tells of you;
and bask in how Merwin speaks directly to the light of September, calling us to notice by noticing.