ἀργύρεια μέταλλα
From LSJ
μήτε δίκην δικάσῃς πρίν ἀμφοῖν μῦθον ἀκούσῃς → do not give your judgement until you have heard a speech on both sides
argenti fodinae, silver mines, 2.55.1, 6.91.7, [in utroq. loco nonnulli codd. in both places some manuscripts ἀργύρεα.]