I was a thrown a bit too with that sentence, otherwise I liked this piece.
I don't presume to speak for the author so there might actually be a thing called a chilmu that I just never heard of, but I thought that the sentence was just a copy/paste error because it makes sense when you read like this:
He was sitting cross-legged on the floor much as a child might, within an arm's length of the peaceful, quiet nothingness of death.
and the childmuch as a chilmu part seems like just a mistake.