Come to me in the silence of the night;
Come in the speaking silence of a dream;
Come with soft rounded cheeks and eyes as bright
As sunlight on a stream;
Come back in tears,
O memory, hope, love of finished years.
O dream how sweet, too sweet, too bitter sweet,
Whose wakening should have been in Paradise,
Where souls brimful of love abide and meet;
Where thirsting longing eyes
Watch the slow door
That opening, letting in, lets out no more.
Yet come to me in dreams, that I may live
My very life again though cold in death:
Come back to me in dreams, that I may give
This balanced final line resolves the tension of the previous two shorter lines. The ‘slow door’ at last opens. The two related clauses ‘letting in’ and its opposite ‘lets out no more’ form a rhythmic balanced, but opposing pair, a device known as  chiasmus
Echo