They went to the temple FOR the prayer time (ἐπὶ plus an accusative can be translated as "for") i.e. "for the hour of prayer". Which particular prayer time did they go for? Πέτρος δὲ καὶ Ἰωάννης ἀνέβαινον εἰς τὸ ἱερὸν ἐπὶ τὴν ὥραν τῆς προσευχῆς τὴν ἐνάτην
They went to the temple FOR the prayer time (ἐπὶ plus an accusative can be translated as "for") i.e. "for the hour of prayer". Which particular prayer time did they go for?
Πέτρος δὲ καὶ Ἰωάννης ἀνέβαινον εἰς τὸ ἱερὸν ἐπὶ τὴν ὥραν τῆς προσευχῆς τὴν ἐνάτην