'Dark' in the Bible

He made darkness his secret place; his pavilion round about him were dark waters and thick clouds of the skies.

Let their way be dark and slippery: and let the angel of the LORD persecute them.

I will incline mine ear to a parable: I will open my dark saying upon the harp.

Have respect unto the covenant: for the dark places of the earth are full of the habitations of cruelty.

I will open my mouth in a parable: I will utter dark sayings of old:

Shall thy wonders be known in the dark? and thy righteousness in the land of forgetfulness?

He sent darkness, and made it dark; and they rebelled not against his word.