I have seen him before... Or ?

I have been here before.
But when or how I cannot tell;
I know the grass beyond the door,
The sweet, keen smell.
The sighing sound, the lights around the shore.

You have been mine before -
How long ago I may not know;
But just when at that swallow's soar
Your neck turned so,
some veil did fall, - I knew it all of yore.

Do you remember ? I do...
Has this been thus before ?
And shall not thus time's eddying flight
Still with our lives love restore...
And day and night yield one delight once more ?