John Calvin on Matthew 17:7

7. Then Jesus approaching touched them. Christ raises them up when they had fallen, and by so doing performs his office; for he came down to us for this very purpose, that by his guidance believers might boldly enter into the presence of God, and that his majesty, which otherwise would swallow up all flesh, might no longer fill them with terror. Nor is it only by his words that he comforts, but by touching also that he encourages them.