Source: The Great Interpretation of Dreams (Ibn Sirin)
Istikhara prayer in a dream indicates seeking guidance from God in a matter and trusting in Him.
Source: Perfuming Humanity in the Expression of Dreams (Al-Nabulsi)
Istikhara prayer indicates confusion in a matter and seeking guidance.
Source: Signs in the Science of Expressions (Ibn Shaheen)
Istikhara prayer is interpreted as goodness and guidance.