ποταμῷ γὰρ οὐκ ἔστιν ἐμβῆναι δὶς τῷ αὐτῷ → it is impossible to step twice in the same river, you cannot step twice into the same rivers
κέμφος ή κέμπος, ὁ (Α)(εσφ. γρφ. αντί κέπφος) μικρό θαλάσσιο πτηνό.