The speaker begins by saying what he is not: a Moses, someone who hears a divine voice in lightning and thunder. No grand revelation comes to him. He feels unseen, and he admits he can't see others either without light, so the problem of being unrecognized runs both ways.
The second stanza turns to the body. A cyst on his neck makes him feel ugly, and graying hair on his chest and groin signals to him that his potential has died. Aging and self-doubt are tied together here, and the tone is frank, almost clinical.
Then the poem shifts. Just as the earth needs rain at the right time, he suggests, he must take stock and "redraw" his dreams. The mood moves from low-key gloom to quiet resolve. He doesn't get a miracle, so he decides to face an uncertain future with plain determination, which feels more human than heroic.