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.
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.
In reference to the use of the sign X with the converting factor, it should be observed that " lb X " symbolizes the replacing of so many times 4 lb by the same number of times 7 lb, while " 4 X " symbolizes the replacing of 4 times something by 7 times that something.