Entering an unknown dungeon or prison signifies the grave, because prison is the grave of the living. If the prison is a known place, the dream signifies sorrow, grief, and distress.
Seeing oneself in a prison resembling a house signifies marrying a woman and receiving wealth and children through her.
Seeing oneself imprisoned in a room signifies goodness and benefit.
Leaving prison but then entering it again signifies returning once more to sin and bad deeds.
Escaping from prison signifies deliverance from hardship and difficulty, or death.
Ja'far al-Sadiq said: Entering a prison and immediately leaving it signifies fully attaining what one desires.