Matthew 17:9-13

9 And as they were coming down the mountain, Jesus commanded them, "Tell no one the vision, until the Son of man is raised from the dead."

10 And the disciples asked him, "Then why do the scribes say that first Eli'jah must come?"

11 He replied, "Eli'jah does come, and he is to restore all things;

12 but I tell you that Eli'jah has already come, and they did not know him, but did to him whatever they pleased. So also the Son of man will suffer at their hands."

13 Then the disciples understood that he was speaking to them of John the Baptist.