Müller, Ulrich B.: Prophetie und Predigt im Neuen Testament: Formgeschichtliche Untersuchungen zur urchristlichen Prophetie. Studien zum Neuen Testament, vol. 10. Gütersloh: Gerd Mohn, 1975.
This Habilitationsschrift (doctoral dissertation) is one of the most important investigations of the problem of prophecy and preaching in the NT where the second part (pp. 47-107) is a detailed analysis mainly of Revelation 2-3 treating the prophecy as the utterings of Christ and the Spirit and analysing the seven messages under two perspectives: as preaching to repentance (Bußpredigt) and preaching to salvation (Heilspredigt).
Müller’s analysis should without doubt be consulted to any analysis of these chapters. (2 Jan 1998).