Islamic Interpretation of Dreams (Ibn-i Sirin):
(Burrow; Hole; Underground passage) In a dream, a tunnel represents trickery and deception.
Ifone sees himselfdigging a tunnel or a hole for someone else in a dream, it means tricking and deceiving him.
If one enters the tunnel that he dug in the dream, it means that he will fall in his own trap.
Ifone enters a tunnel or a burrow and cannot see light at the end of it, or if a traveller digs a hole, enters it and can longer see the skies or the stars above him in the dream, it means that thieves will rob him from his luggage, or that he will be highjacked, or stopped by a band of highway robbers.
If one sees himself taking an ablution or a bath inside the tunnel or in the hole in a dream, it means that he will arrest the robbers and recover his property.
Ifone enters a tunnel and takes a bath inside it in a dream, it means that he will pay his debts, or repent for his sins, or ifhe is incarcerated, it means that he will be released.
Ifone digs a tunnel and draws water from it or discovers a hole filled with still water inside it in a dream, it means that he earns his livelihood from trickery and deception.
(Also see Piercing a hole)