Source: The Great Interpretation of Dreams (Ibn Sirin)
Eating dirt in a dream indicates extreme poverty and need, or death.
Source: Perfuming Humanity in the Expression of Dreams (Al-Nabulsi)
Eating dirt indicates gaining wealth proportionate to the amount eaten.
Source: Signs in the Science of Expressions (Ibn Shaheen)
Eating dirt is interpreted as wealth. Whoever sees himself eating it will gain wealth.