He. Dear, I must be gone
While night Shuts the eyes
Of the household spies;
That song announces dawn.

She. No, night's bird and love's
Bids all true lovers rest,
While his loud song reproves
The murderous stealth of day.

He. Daylight already flies
From mountain crest to crest

She. That light is from the moon.

He. That bird...

She. Let him sing on,
I offer to love's play
My dark declivities.

William Butler Yeats

http://www.poemhunter.com/poem/parting-3/