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 #3217
3217. When angels' discussion has to do with the understanding part of the mind, horses appear in the world of spirits below them, that is, in the communities which correspond to them. The size, shape, colour, and stance of the horses depends on the ideas which the angels have concerning the understanding. The horses also carry differing adornments. There is also a place quite deep down and a little towards the right which is called the abode of the intelligent. There horses are seen constantly, the reason being that those there are engaged in thought about the understanding; and when the angels who are engaged in a discussion about the understanding flow into the thoughts of those spirits, horses are seen. From this I have come to see what was meant by the horses seen by the prophets, and also by the horses mentioned in the Word, namely aspects of the understanding, 2760-2762.