“And Jesus seeing the multitudes went up into the mountain, and when He was set, His disciples came unto Him. And He opened His mouth, and taught them…” (Matthew 5:1-2; prologue to the Sermon on the Mount)….
See how unambitious He was, and void of boasting, in that He did not lead people about with Him.
When healing was required, He had Himself gone about everywhere, visiting both towns and country places.
Now when the multitude is become very great, He sits in one spot; and that not in the midst of any city or forum, but on a mountain and in a wilderness.
And He instructs us to do nothing for display, and to separate ourselves from the tumults of ordinary life, and this most especially, when we are to study wisdom, and to discourse of things needful to be done.
But when He had gone up into the mount, and “was set down, His disciples came unto Him.”
Do you see their growth in virtue, and how in a moment they became better men?
Since the multitude were but gazers on the miracles, but these from that hour desired also to hear some great and high thing.
And indeed this it was set Him on His teaching, and made Him begin this discourse.
For it was not men’s bodies only that He was healing, but He was also amending their souls; and again from the care of these He would pass to attendance on the other.
Thus He at once varied the succour that He gave, and likewise mingled with the instruction afforded by His words the manifestation of His glory from His works.
And besides, He stopped the shameless mouths of the heretics, signifying by this His care of both parts of our being, that He Himself is the Maker of the whole creation.
Therefore also on each nature He bestowed abundant providence, now amending the one, now the other. And in this way He was then employed. For it is said, that “He opened His mouth, and taught them.”
And wherefore is the clause added, “He opened His mouth”? To inform us that in His very silence He gave instruction, and not when He spoke only, but at one time by “opening His mouth,” at another uttering His voice by the works which He did.
But when you hear that He taught them, do not think of Him as discoursing with His disciples only, but rather with all through them.
For since the multitude was such as a multitude ever is, and consisted moreover of such as creep on the ground, He withdraws the choir of His disciples, and makes His discourse unto them.
In His conversation with them He provides that the rest also, who were yet very far from the level of His sayings, might find His lesson of self-denial no longer grievous unto them.
John Chrysostom (c.347-407): Homilies on the Gospel According to St Matthew, 15, 1 (on Matthew 5:1-2); slightly adapted.