Recently, I watched a video by Shinzen Young in which he discussed several perspectives on the "witness" and related that to the "absolute" or the "nondual" or the "source" in Buddhist (and other contemplative) thought.
You can view the video here
(it doesn't allow embedding).
In relation to this video, there is a "practice-oriented" document by Young that might be worth checking out, which I have attached to this thread. (It was shared with me by C4Chaos on Facebook).
I am posting these items here because I think it might be interesting to explore these ideas (and the related practices) in relation to some of our recent discussions (of Levin, of context-transcendent meaning or experience, of Derrida's khora vs. Wilber's emptiness, etc).
I'm very busy today and can't comment more now, but will return with a few thoughts in the next day or two.