Source: The Great Interpretation of Dreams (Ibn Sirin)
A sponge in a dream indicates a servant or a child. It indicates a man who gathers money.
Source: Perfuming Humanity in the Expression of Dreams (Al-Nabulsi)
A sponge indicates a man who strives for people's interests. Seeing it indicates goodness.
Source: Signs in the Science of Expressions (Ibn Shaheen)
A sponge is interpreted as goodness. Whoever sees himself owning it will attain goodness.