The phrase gives expression to the intensity of the pain people felt because of the blackness (hopelessness) into which God had plunged them through the fifth bowl. The term recalls Jesus’ words when he described the horrors of God’s judgment in “the outer darkness. In that place there will be weeping and gnashing of teeth” (Matthew 25:30; see further Matthew 13:42, Matthew 13:50; Matthew 24:51). The darkness that people experience when God takes away any remaining vestige of hope is an earthly foretaste of hell.
10 The fifth angel poured out his bowl on the throne of the beast, and its kingdom was plunged into darkness. People gnawed their tongues in anguish