If it wasn't meant to negate a spell on him right now... in dath ilan, this would be a message to the effect of, think about what spells could be cast on you that you wouldn't want cast on you, maybe.)
Keltham catches the word "Iomedae." Comprehend Languages, gesturing the spell slowly so they can see it. "Iomedae?" Keltham says after casting; he can hear, now, but can't speak.