Then the disciples understood that he was speaking to them of John the Baptist.
We have here the story of Christ's transfiguration; he had said that the Son of man should shortly come in his kingdom, with which promise all the three evangelists industriously connect this story; as if Christ's transfiguration were intended for a specimen and an earnest of the kingdom of Christ, and of that light and love of his, which therein appears to his select and sanctified ones.
Commenting on Matthew 17:1-13
Then the disciples understood,.... By his saying that Elias was come, and by the account he gave of his ill usage, it was clear to them, that he spake unto them of John the Baptist; and that he was the Elias that was to come, and was come: so that this observation, that according to prophecy Elias was to come before the Messiah, was no...