'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.

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

220. 'His voice going to and fro' means that only a residue of perception was left, so small as to be solitary and inaudible, so to speak. This is also clear from the next verse in which it is said that Jehovah called out to the man. A similar usage occurs in Isaiah,

The voice of one crying in the wilderness; the voice said, Cry! Isaiah 40:3, 6.

'Wilderness' stands for a Church where no faith exists; 'the voice of one crying stands for the declaration of the Lord's coming, in general for every declaration of His coming, as is made to regenerate persons who have this dictate residing in them.