'Deep' in the Bible

"They didn't ask, "Where is the LORD who brought us up from the land of Egypt, who led us through the wilderness, through the land of desert and pits, through the land of dryness and deep darkness, a land that people don't pass through, and where no one lives?'

Give glory to the LORD your God before he brings darkness, before your feet stumble on the mountains at twilight. You hope for light, but he turns it into deep darkness. He changes it into heavy gloom.