'The first resurrection,' mentioned in Revelation 20:5, 6, does not mean a first resurrection, but the essence and primary part of resurrection, which is salvation and eternal life. There is only one resurrection to life. A second does not happen, and is not mentioned anywhere in the Bible.

(References: Apocalypse Explained 6; Apocalypse Revealed 851; Revelation 20:5-6)

'The Nile' or 'river of Egypt' represents the sensory things subject to the intellectual mind and the ideas derived there. This is because they are the extreme parts of the spiritual things in the Lord's kingdom.

(References: Arcana Coelestia 5196)