Quote by Emily Dickinson

My life closed twice before its' close-
It yet remains to see
If Immortality unveil
A third event to me. So huge, so hopeless to concieve As these that twice befell. Parting is all we know of heaven, And all we need of hell.

Please suggest source details if you know: book, page, year, online article address (url), correction (different author...), etc.. Thanks.