A.T. Robertson Commentary Revelation 22:20

"He who testifieth these things saith, Yea: I come quickly. Amen: come, Lord Jesus." — Revelation 22:20 (ASV)

He which testifieth (ο μαρτυρων). That is Jesus (1:2) who has just spoken (22:18).Yea: I come quickly (Ναι, ερχομα ταχυ). Affirmation again of the promise in 22:7,12. On Να (Yes) see 1:7 for the Lord's assent to the call. Then John expresses his absolute belief in the Lord's promise: "Amen: come, Lord Jesus" (Αμην, ερχου, Κυριε Ιησου). On Αμην see 1:7. On ερχου see 22:17. Note Κυριε with Ιησου. As in 1 Corinthians 12:3; Php 2:11. For Paul's confidence in the deity of Christ and the certainty of his second coming see Tit 2:13; 2 Timothy 4:8. Μαρανα θα (1 Corinthians 16:22).