Resurrection, the first
'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)
Arcana Coelestia #715
715. Since the most ancient people knew and when in self-abasement acknowledged that they were nothing but beasts and wild animals, and that the Lord alone enabled them to be human beings, they not only used to liken whatever resided with themselves to beasts and birds but also called them such. Things of the will they compared to beasts and called them beasts, and those of the understanding they compared to birds and called them birds. They differentiated however between good affections and evil affections. Good affections they compared to lambs, sheep, kids, he-goats, young she-goats, rams, young bulls, and oxen, because they were good and gentle creatures, and also because they had a use in life in that they could be eaten and men could clothe themselves with their skins and wool. These are chiefly the clean beasts. But the evil and savage ones, which also have no use in life, are unclean beasts.