Your heart, Mary Karr, he'd say. His pen touched my sternum, and it felt for all the world like the point of a dull spear as he said, Your heart knows what your head don't. Or won't.
There's a space at the bottom of an exhale, a little hitch between taking in and letting out that's a perfect zero you can go into. There's a rest point between the heart muscle's close and open - an instant of keenest living when you're momentarily dead. You can rest there.