ἀνήκεστόν τι δρᾶν
From LSJ
τότε λαλήσει πρὸς αὐτοὺς ἐν ὀργῇ αὐτοῦ καὶ ἐν τῷ θυμῷ αὐτοῦ ταράξει αὐτούς → then shall he speak to them in his anger, and trouble them in his fury
Greek > English (Woodhouse)
take extreme measure, take extreme measures, take strong measures