'Darkness' in the Bible

And ye came near and stood under the mountain; and the mountain burned with fire unto the midst of heaven, with darkness, clouds, and thick darkness.

These words the LORD spake unto all your assembly in the mount out of the midst of the fire, of the cloud, and of the thick darkness, with a great voice: and he added no more. And he wrote them in two tables of stone, and delivered them unto me.

And it came to pass, when ye heard the voice out of the midst of the darkness, (for the mountain did burn with fire,) that ye came near unto me, even all the heads of your tribes, and your elders;

And thou shalt grope at noonday, as the blind gropeth in darkness, and thou shalt not prosper in thy ways: and thou shalt be only oppressed and spoiled evermore, and no man shall save thee.