LXX Num 22:38

καὶ εἶπεν Βαλαὰμ πρὸς Βαλάκ ἰδοὺ ῆκω πρὸς σὲ νῦν· δυνατὸς ἔσομαι λαλῆσαί τι; τὸ ῥῆμα ὃ ἐὰν βάλῃ ὁ θεὸς εἰς τὸ στόμα μου, τοῦτο λαλήσω.

“See, I have come to you,” Balaam replied, “but can I say just anything? I must speak only the word that God puts in my mouth.”