NET
11 You approached and stood at the foot of the mountain, a mountain ablaze to the sky above it and yet dark with a thick cloud.
Darby
11 And ye came near and stood under the mountain; and the mountain burned with fire to the heart of heaven, with darkness, clouds, and obscurity.
KJV
11 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.