In Philo the wild pigeon symbolizes the holy spirit.
The mutual love of these two, proceeding from the relation they hold to one another, symbolizes the Holy Spirit.
The former symbolizes his metaphysical conception, which was suggested to him by his reading of Spinoza.
The pastoral staff, as its name implies, symbolizes the pastoral office and authority, a symbolism already known to Isidore of Seville (De ecclesiast.
This, of course, symbolizes the Ascension; but meanwhile the other lamps in the church have received their light from the Paschal Candle, and so symbolize throughout the year the continued presence of the light of Christ.