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
fig. cegar πρὸς τὸ τῆς ἀλήθειας φῶς Gr.Naz.M.36.257D (pero u.l. ἀμβλυόττω).
