Originally Posted by ghop
I would not overly analyze this, as it is more a knowing in the doing. Otherwise, it is like asking what the experience of "eating ice cream" is ... which is something to be known in experience, not words.
However, I would say that "turning the light inward" is to just sit vibrantly, yet unattached to conditions within or without (not two). Dogen wrote in Fukanzazengi "learn the backward step that turns your light inwardly to illuminate your self." Another translation is "allow the external seeking of your mind to collapse upon itself and light up your own nature".
The Ancestor Shitou wrote, "Turn around the light to shine within, then just return. . . . Let go of hundreds of years and relax completely."
Our senses are usually pointed outward, grasping and judging. Even when we think about our selves, our lives, we judge it as an object (we judge our life like we judge everything, with aversions, attractions. We have attachments.). Withdraw all that looking and judging outward. turning the light around. Let that light just shine.
Does that shed some light on the question?
Gassho, Jundo (written from the road)