'Dark' in the Bible

"When you approached and stood at the foot of the mountain a mountain that was blazing with fire at its core while the sky was covered with thick, dark clouds

"The LORD declared these commands in a loud voice to your entire assembly on the mountain from out of the fire and dark clouds, and nothing more was added. He inscribed them on two tablets of stone and gave them to me.

And after hearing the voice which came out of the dark while the mountain was burning with fire, all the heads of your tribes and your chiefs came to me,

so that at noon you will grope as a blind man gropes in the dark. You will not be successful in anything you do. You will only be oppressed and robbed continually, and no one will help you.

Your very life will be hanging in doubt before you, and day and night will be dark with fears, and nothing in life will be certain: