Apocalypse Revealed #448
448. And I heard the number of them. This symbolizes their character perceived, that it was as described hereafter.
To hear means, symbolically, to perceive. A number symbolizes the character of a thing or a state (nos. 10, 348, 364). It is the character of these people's state as described hereafter because that is what is now described in the following verses, which is why it begins, "And thus I saw."
