Parallel
Mark 9:10
Nestle 1904 Greek New Testament · Berean Standard Bible
καὶ τὸν λόγον ἐκράτησαν πρὸς ἑαυτοὺς συζητοῦντες τί ἐστιν τὸ ἐκ νεκρῶν ἀναστῆναι
So they kept this matter to themselves, discussing what it meant to rise from the dead.