Suidas, Lexicon, s. v. Κεραμεύειν.
To make pottery: commonly said instead of “to work hard.”
Κεραμεύειν. κοινῶς ἀντὶ τοῦ κατεργάζεσθαι.
Hesiod, Works and Days, 25 f.
Potter bears a grudge against potter, and carpenter against carpenter, and beggar envies beggar, and minstrel is jealous of minstrel.
Καὶ κεραμεὺς κεραμεῖ κοτέει καὶ τέκτονι τέκτων
καὶ πτωχὸς πτωχῷ φθονέει καὶ ἀοιδὸς ἀοιδῷ.
Aristotle, Rhetoric, 2, 4, 21, 22.
[We are friendly towards] our equals, and towards those who have the same interests, if they do not clash with us, and if their livelihood does not come from the same source, for thus arises the proverb “Potter hates potter.”
Καὶ τοὺς ὁμοίους καὶ ταὐτὰ ἐπιτηδεύοντας, ἐὰν μὴ παρενοχλῶσι μὴ δ’ ἀπὸ ταὐτοῦ ὁ βίος. γίγνεται γὰρ οὕτω τὸ κεραμεὺς κεραμεῖ.