κανθήλιον

From LSJ

Καὶ τῶν λεγόντων εὖ καλὸν τὸ μανθάνειν → It is a fine thing to learn from those who speak well

Sophocles, Antigone, 722

Russian (Dvoretsky)

κανθήλιον: τό ослиная шкура (τὸ κ. ἐνδύεσθαι Plut.).