9:12 Elijah verily coming first restoreth all things: and how it is written - That is, And he told them how it is written - As if he had said, Elijah's coming is not inconsistent with my suffering. He is come: yet I shall suffer. The first part of the verse answers their question concerning Elijah; the second refutes their error concerning the Messiah's continuing for ever.
9:1-13 Here is a prediction of the near approach Christ's kingdom. A glimpse of that kingdom was given in the transfiguration of Christ. It is good to be away from the world, and alone with Christ: and how good to be with Christ glorified in heaven with all the saints! But when it is well with us, we are apt not to care for others, and in the fulness of our enjoyments, we forget the many wants of our brethren. God owns Jesus, and accepts him as his beloved Son, and is ready to accept us in him. Therefore we must own and accept him as our beloved Saviour, and must give up ourselves to be ruled by him. Christ does not leave the soul, when joys and comforts leave it. Jesus explained to the disciples the prophecy about Elias. This was very suitable to the ill usage of John Baptist.