τὸ πλῆθος οὐκ εὐαρίθμητον ἦν → the crowd wasn't easy to count, the crowd was not small, it was not a small crowd
ἐπέσσευεν: ἐπεσσεύοντο, ἴδε τὸ ῥῆμα ἐπισεύω.