Source: The Great Interpretation of Dreams (Ibn Sirin)
A thorn in a dream indicates a man of difficult temperament. It entering the body indicates falling into strife or debt.
Source: Perfuming Humanity in the Expression of Dreams (Al-Nabulsi)
A thorn indicates worry and grief. Removing it indicates the removal of worry.
Source: Signs in the Science of Expressions (Ibn Shaheen)
A thorn is interpreted as worry. Whoever sees it entering his hand will be afflicted with worry.