The heaven shall reveal his iniquity, i.e. God shall be a swift witness against him by some extraordinary judgments: still he reflects upon Job's case, and the fire from heaven, Job 1. The earth i.e. all creatures upon earth shall conspire with God to destroy him.
Related Commentaries of Job 20:27
Job 20:27
27 The heaven shall reveal his iniquity; and the earth shall rise up against him.