'Mightily' in the Bible

Men shall go into the caves of the rocks, and into the holes of the earth, from before the terror of Yahweh, and from the glory of his majesty, when he arises to shake the earth mightily.

To go into the caverns of the rocks, and into the clefts of the ragged rocks, from before the terror of Yahweh, and from the glory of his majesty, when he arises to shake the earth mightily.