Charles Ellicott Commentary Job 20:26

"All darkness is laid up for his treasures: A fire not blown [by man] shall devour him; It shall consume that which is left in his tent." — Job 20:26 (ASV)

All darkness shall be hid in his secret places. —Rather, All darkness, every kind of disaster, is laid up for his secret treasures.

A fire not blown. —By human hands, etc.