Larry Eigner's poem is only a handful of words, spread thinly down the page, and that spacing is part of how it works. You read it slowly, one word at a time, almost the way you might watch the sky before a storm.
The speaker seems to be asking us to look at things as they are, each one a "combination" of something "or another." Nothing is fixed. The poem doesn't say what is being seen, only that the world arrives as shifting arrangements. Then it lands on "possibilities of rain," a phrase that turns the whole thing toward waiting. Rain hasn't come yet, but it might.
The mood is quiet, attentive, and a little open-ended. The speaker doesn't sound anxious or excited. They sound curious, content to notice and let things stay uncertain. The short lines leave pauses, so the poem feels like a held breath, full of what could happen next.