The speaker watches a rural October evening settle in, and the poem moves the way the eye does, picking out one thing after another. It opens with an odd question, "What do you mean / by knife, by wind?", as if the speaker is puzzling over the words themselves. The knife comes back a few lines later, when the horizon becomes a blade and the blue sky a slice of fruit riding along it. The image is sharp but also oddly tasty, "delectable."
Then the view widens to a half moon over a barn, and a field of goldenrod full of sparrows blending "brown into brown." "Poor Sam Peabody" seems to be a bird's call, heard as a faltering song that "catches in the middle / like a shirt on a thorn." That is the poem's most tender, slightly comic moment.
The mood is quiet, observant, and a little melancholy. As the wind drops, the colors darken "like dried blood," a final image that is beautiful and faintly ominous, as though the day has been wounded and is now going still.