The people stood far off, while Moses drew near to the thick darkness where God was. - Exodus 20:21 

When I read about the "thick darkness,” it reminds me of my father's darkroom where I learned to develop film many years ago. (Note to young readers: Ask your parents or maybe your grandparents about film. Maybe they remember and can explain it to you.) The precious exposed film could only be handled in total darkness. A proper photographic darkroom is one of the few places where darkness is really, truly dark. Dad taught me to do everything about the process in total darkness — from opening the rolls of film to loading them onto the stainless steel spiral reels and putting them into the tanks containing the developer, stop and fix bath. I learned to do it all by touch, not sight. In the darkroom, I could hold my hand in front of my face and see nothing at all. It could have been scary, but not when my father was there in the darkness with me.