Hesiod, Works and Days
265-269 (tr. Glenn W. Most):
A man contrives evil for himself when he contrives
evil for someone else, and an evil plan is most evil for the
planner. Zeus' eye, which sees all things and knows all
things, perceives this too, if he so wishes, and he is well
aware just what kind of justice this is which the city has
οἷ γ᾽ αὐτῷ κακὰ τεύχει ἀνὴρ ἄλλῳ κακὰ τεύχων,
ἡ δὲ κακὴ βουλὴ τῷ βουλεύσαντι κακίστη.
πάντα ἰδὼν Διὸς ὀφθαλμὸς καὶ πάντα νοήσας
καί νυ τάδ᾽, αἴ κ᾽ ἐθέλῃσ᾽, ἐπιδέρκεται, οὐδέ ἑ λήθει,
οἵην δὴ καὶ τήνδε δίκην πόλις ἐντὸς ἐέργει.
M.L. West on line 267: