They set their mouth against the heavens, and their tongue walketh through the earth.
They set their mouth against the heavens. With their blasphemies they even reach up to heaven itself, denying the providence and moral government of God Himself. The same Hebrew [bª-] stands for "against" and "through;" translate, 'in the heavens ... in the earth.' So the Beast (Revelation 13:6).
And their tongue walketh through the earth - they go up and down, ever restless, like their master, Satan (Job 1:7; Job 2:2), seeking for matter of foul-mouthed censure alike in things above and below.