μὴ κακὸν εὖ ἔρξῃς· σπείρειν ἴσον ἔστ' ἐνὶ πόντῳ → do no good to a bad man; it is like sowing in the sea
Ar. and P. λήκυθος, ἡ, ληκύθιον, τό; see also jar.