These words are from William Butler Yeats poem "The Second Coming":

Surely some revelation is at hand.

Surely the Second Coming is at hand.

The Second Coming! Hardly are those words out

When a vast image out of the Spiritus Mundi troubles my sight.

The darkness drops again; but now I know

That twenty centuries of stony sleep

Were vexed to nightmare by the rocking cradle,

And what rough beast, it hour come round at last,

Slouches towards Bethlehem to be born?