'Darkness' in the Bible

And Jehovah said unto Moses, Stretch out thy hand toward heaven, that there may be darkness over the land of Egypt, even darkness which may be felt.

And Moses stretched forth his hand toward heaven; and there was a thick darkness in all the land of Egypt three days;

and it came between the camp of Egypt and the camp of Israel; and there was the cloud and the darkness, yet gave it light by night: and the one came not near the other all the night.

And the people stood afar off, and Moses drew near unto the thick darkness where God was.