A.T. Robertson Commentary Revelation 21:3

"And I heard a great voice out of the throne saying, Behold, the tabernacle of God is with men, and he shall dwell with them, and they shall be his peoples, and God himself shall be with them, [and be] their God:" — Revelation 21:3 (ASV)

The tabernacle of God is with men (η σκηνη του θεου μετα των ανθρωπων). It is one of the angels of the Presence (16:17; 19:5) speaking.

And he shall dwell with them (κα σκηνωσε μετ' αυτων). Future active of σκηνοω, already in 7:15 from Eze 37:27; Zechariah 2:10; 8:8 and used of the Incarnate Christ on earth by John (John 1:14), now a blessed reality of the Father. The metaphor stands for the Shekinah Glory of God in the old tabernacle (7:15; 13:6; 15:5), the true tabernacle of which it was a picture (Hebrews 8:2; Hebrews 9:11). God is now Immanuel in fact, as was true of Christ (Matthew 1:23).