Matthew 3:12

whose winnowing shovel is in his hand, and he will thoroughly clean his threshing floor, and gather his wheat into the storehouse; but the chaff he will burn with an inextinguishable fire.

Matthew 8:12

but the children of the kingdom shall be cast into the darkness outside; there shall be weeping and gnashing of teeth.

Jude 1:13

wild waves of the sea foaming with their own shame, wandering stars to which is reserved the blackness of darkness for ever.

Treasury of Scripture Knowledge

Summary

All darkness shall be hid in his secret places: a fire not blown shall consume him; it shall go ill with him that is left in his tabernacle.

A fire

Bible References

Darkness

Matthew 8:12
but the children of the kingdom shall be cast into the darkness outside; there shall be weeping and gnashing of teeth.
Jude 1:13
wild waves of the sea foaming with their own shame, wandering stars to which is reserved the blackness of darkness for ever.

A fire

Matthew 3:12
whose winnowing shovel is in his hand, and he will thoroughly clean his threshing floor, and gather his wheat into the storehouse; but the chaff he will burn with an inextinguishable fire.