Δελφῖνα νήχεσθαι διδάσκεις: ἐπὶ τῶν ἐν ἐκείνοις τινὰ παιδοτριβούντων, ἐν οἷς ἤσκηται → Teaching dolphins to swim: is applied to those who are teaching something among people who are already well versed in it
χέρρας: Αἰολ. αἰτ. ἀντὶ χεῖρας, δῶρον Νικιάας εἰς ἀλόχω χέρρας ὀπάσσομεν Θεόκρ. 28, 9.
χέρρας: Theocr. acc. pl. к χείρ.
