Authors:

I sent my Soul through the Invisible, Some letter of that After-life to spell: And by and by my Soul return'd to me, And answer'd: 'I Myself am Heav'n and Hell

Omar Khayyam, Edward FitzGerald, Christopher Decker (1997). “Edward FitzGerald, Rubáiyát of Omar Khayyám: A Critical Edition”, p.189, University of Virginia Press
I sent my Soul through the Invisible, Some letter of that After-life to spell: And by and by my Soul return'd to me, And answer'd: 'I Myself am Heav'n and Hell