Dirk Jongkind has posed some interesting questions about the syntactical construction of Greek prepositions in Revelation. Looking specifically at chapter 4, Jongkind notes,

I was looking at Revelation 4:9 where the text reads τῷ καθημένῳ ἐπὶ τῷ θρόνῳ with the variant ἐπὶ τοῦ θρόνοῦ. . . . In the construction ‘he who sits on the throne’ the case of the prepositional phrase ‘on the throne’ (ἐπί + article + θρόνος) that follows the participle ‘he who sits’ is normally identical to the case of the participle.

So we have ἐπὶ τοὺς θρόνους … καθημένους (4:4); τῷ καθημένῳ ἐπὶ τῷ θρόνῳ (4:9); τοῦ καθημένου ἐπὶ τοῦ θρόνου (4:10).

There are a number of exceptions. With the nominative (ὁ) καθήμενος we find both ἐπὶ τῷ θρόνῳ (21:5) and ἐπὶ τὸν θρόνον (4:2) and with other combinations of κάθημαι ἐπί (e.g. with αὐτός) it doesn’t apply as much. It would be nice if someone could give a good linguistic explanation of this phenomenon.

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