Student: Could you say something about what you mean by heaven and earth?
Chögyam Trungpa:: What do you think it could be? Do you have any ideas?... What's earth?
S: Well, that's where I'm sitting.
CT: Good. From that, you can tell what heaven is. It's our reference point with each other.
S: But that sounds like being in the middle of a sandwich.
CT: Well, maybe you are in a sandwich. We're always sandwiched because we have a past, we have a present, and we have a future. We are sandwiched by our father, our mother, our child. Even timewise, we are sandwiched. We are sandwiched between breakfast, lunch and dinner.
From "How to Cultivate the Great Eastern Sun," in Great Eastern Sun: The Wisdom of Shambhala, pages 112 to 113.