ἀπιστητέον
From LSJ
ὃν οὐ τύπτει λόγος οὐδὲ ῥάβδος → if words don't get through, neither a beating will | if the carrot doesn't work, the stick will not work either | whom words do not strike, neither does the rod
English (LSJ)
one must mistrust, disbelieve, c. dat., Plb.4.41.8; of persons, Str.8.4.10, etc.; ἀ. ἡμῖν περί . . Hp.Cord.2.
Greek (Liddell-Scott)
ἀπιστητέον: ῥημ. ἐπίθ. τοῦ ἀπιστῶ, δεῖ ἀπιστεῖν, πρέπει τις νὰ ἀπιστῇ ἢ νὰ δυσπιστῇ, μετὰ δοτ., Πολύβ. 4. 41, 8, Στράβ. 362.
Spanish (DGE)
no hay que creer, hay que desconfiar c. dat. de cosa τῷ μεγέθει ... τῷ πλήθει Plb.4.41.8
•c. dat. de pers. ἡμῖν περί ... Hp.Cord.2, τῷ φήσαντι Str.8.4.10.