Source: The Great Interpretation of Dreams (Ibn Sirin)
A grandson in a dream indicates extension of life, offspring, and approaching goodness.
Source: Perfuming Humanity in the Expression of Dreams (Al-Nabulsi)
A grandson indicates joy and blessing in wealth and children.
Source: Signs in the Science of Expressions (Ibn Shaheen)
A grandson is interpreted as goodness and benefit. Seeing him indicates an increase in sustenance.