Enter into the rock. The limestone rocks of Palestine are full of extensive caverns, to which the Israelites often betook themselves in times of danger (see 6:2; 1 Samuel 13:6; 1 Samuel 22:1, etc.). The prophet exhorts them to flee thither now, but without stating what exactly is the peril (comp.
Isaiah 2:19, Isaiah 2:21). Hide thee in the dust. Not "the dust of humiliation" (Kay), but "the dust of the earth" (Genesis 2:7), put here for the earth itself, as in Isaiah 2:19. For fear of the Lord; rather, from before the terror of Jehovah.
Some awful manifestation of Jehovah's power is intended, its nature being still kept back and shrouded in darkness.