Source: The Great Interpretation of Dreams (Ibn Sirin)
Prayer in the mosque indicates following the Sunnah, fulfillment of needs, and safety from fear. Whoever sees himself praying in the mosque will attain goodness and sustenance.
Source: Perfuming Humanity in the Expression of Dreams (Al-Nabulsi)
Prayer in the mosque indicates profitable trade. Whoever sees himself leading prayer in the mosque will gain a position of power.
Source: Signs in the Science of Expressions (Ibn Shaheen)
Prayer in the mosque is interpreted as goodness and blessing. Whoever sees himself praying in it, his affairs will be rectified.