Your hooves have stamped at the black margins of the wood,
Even where horrible green parrots call and swing.
My works are all stamped down in the sultry mud.
I knew that horse-play, knew it for a murderous thing.
What wholesome sun has ripened is wholesome food to eat,
And that alone; yet I, being driven half insane
Because of some green wing, gathered old mummy wheat
In the mad, abstract dark and ground it grain by grain
And after baked it slowly in an oven; but now
I bring full-flavoured wine out of a barrel found
Where seven Ephesian topers slept and never knew
When Alexander’s empire passed, they slept so sound.
Stretch out your limbs and sleep a long Saturnian sleep;
I have loved you better than my soul for all my words,
And there is none so fit to keep a watch and keep
Unwearied eyes upon those horrible green birds.
A centaur is a symbol of wanton male sexuality. Its blackness denotes covert or immoral events such as adultery, outside the light. Indeed Yeats says in the poem “Your hooves have stamped at the black margins of the wood” which means he, the centaur, has been active outside his area, in other words committing adultery.
The “horrible green parrots” are Irish nationalists whose colour is green, and who were then parroting political demands. Thus when he says he is “...being driven half insane / Because of some green wing...” he is referring to his lover from that section of society. Lily, a working class Catholic girl, was well acquainted with “those horrible green birds”.
He admits “I knew that horse-play...” meaning sex outside marriage, though he knows he ought to have stayed with “...what wholesome sun has ripened...” in other words his wife, George.
Nevertheless he has “gathered old mummy wheat …”. Wheat from the tombs of Egyptian mummies had been discovered to sprout centuries later, when removed from the dark and brought into the light. Yeats is talking about his potency; his seeds have sprung to life after having been dead for an age.
“...In the mad, abstract dark... ” refers to night, when sex happens, but also to the illicit nature of it.
His use of the word “mummy” refers to the pregnancies of his lover and George, which occurred in 1919, 1920 and 1921. This “mummy wheat” has been exposed to the sun that has “...baked it...” and turned it into the “...full-flavoured wine...” of new life.
He finishes with “I have loved you better than my soul for all my words...”. This love has been detrimental to his soul, or morality and conscience. For this reason and because of its exultant, joyful intensity it is not written for George. The given date of the poem, September 1920, was just before the birth of Kevin Barry, his illegitimate son by Lily O'Neill, on 9th November 1920.
The previous year his wife had given birth to a daughter, Anne. George “never knew When Alexander’s empire passed”: at last he has his new son, and not by her.
Yeats called Kevin his ‘heir’, his ‘black eagle’ or ‘4th daimon’. George edited the publication of these phrases to make it seem as though she had foreseen the birth of her own son in August the following year, thus enhancing her clairvoyancy since Michael had not yet been conceived.