οἱ τοῖς πέλας ἐπιβουλεύοντες, λανθάνουσι πολλὰκις ὑφ' ἑτέρων τοῦτ' αὐτὸ πάσχοντες → when people plot against their neighbours, they fall victim to the same sort of plot themselves
Use P. and V. ἀνόσιος συνουσία, ἡ, V. συγγενὴς γάμος, ὁ.