Epistles of Phalaris, 13:
If another person had suffered badly at another person’s hands, he would not make an avowal of his intent for revenge against the perpetrator, so that he would not be suspected in his design. I think that it is the act of a vile man to get the better of someone who is unaware. Having, then, been first injured by you, I warn you to take care of the great revenge coming your way from me, so that before the suffering, you can be chastised by the foreknowledge of it, and after the foreknowledge, you can experience the suffering itself.
῎Αλλου μὲν ἦν κακῶς πεπονθότος μηδὲν ὁμολογῆσαι πρὸς τὸν δεδρακότα περὶ ἀμύνης, ἵν’ ὡς ἥκιστα πρὸς αὐτὸν ὕποπτος ἁλῴη, ἐγὼ δὲ τοῦτο μὲν ἀγεννοῦς ἀνδρὸς ἔργον ἡγοῦμαι τὸ τὸν ἀγνοοῦντα χειρώσασθαι. προηδικημένος δ’ ὑπὸ σοῦ μεγάλα μηνύω σοι φυλάττεσθαι τὴν ἐπιοῦσαν ἐξ ἡμῶν ἄμυναν, ἵνα πρὸ τοῦ μὲν παθεῖν ἡ προσδοκία κολάζῃ σε, μετὰ δὲ τὴν προσδοκίαν αὐτὸ τὸ παθεῖν.