599. Verse 2. And he had in his hand a little book opened, signifies the Word laid open. This is evident from the signification of "a little book opened," as being the Word laid open. It can be seen that this is what is meant by "the little book opened," since "the strong angel coming down out of heaven, who had in his hand a little book," represented the Lord as to the Word, and in fact, as to its ultimate sense, which is called the sense of the letter (See above, n. 593); and because the Word was laid open both to angels and men it is said "a little book opened."

Babylon was an ancient city built on the Euphrates river in what is now southern Iraq. It once was the capital of a great empire which at one point conquered the land of Judah as mentioned in the second book of Kings and in Daniel. But the river changed its course and the city was abandoned long ago. Both the historic city in Mesopotamia and the parable city with its tower, mentioned in Genesis, represent the same thing, a worship that appears holy in externals, while the internals are profane. This representation expands to mean a church whose leaders use this kind of worship to gain dominion over others for their own gain and for the gain and power of the church. The city itself is the doctrinal structure that supports this kind of worship and dominion.

(Reference: Apocalypse Explained 1029; Arcana Coelestia 1283, 1302, 1304, 1310, 1311)