Sleep is imagined here as something that nourishes, almost like a parent feeding a hungry creature. The sleeper is "the feeder," and what he is given is dreams. But the meal isn't comforting. Half of life, the poem says, is spent sleeping, digesting the daily struggle to "gather and to grow" or else to "become the grave."
What comes back in the dreams is failure: the "missed mark," unfulfilled hungers, "missed matings, mismatings." The language is bodily and animal, full of meat, seed, heat and rot. Human wishes sound like crops or food that spoil before they can be used. The "dark spirit eyes" of his forefathers watching his "undoing" add a feeling of being judged by those who came before.
The speaker seems resigned more than angry. The mood is uneasy and bleak, and the ending, with the seed dried up, leaves nothing hopeful.