2 When therefore as well by the place, as by his garments, and by their concourse unto Him, He had delineated his character, He proceeds to bring in the prophet. For having said, “Why went ye out? To see a prophet? Yea I say unto you, and more than a prophet;” He goes on, “For this is he of whom it is written, Behold, I send my messenger before Your face, which shall prepare Your way before You.” Having before set down the testimony of the Jews, He then applies that of the prophets; or rather, He puts in the first place the sentence of the Jews, which must have been a very strong demonstration, the witness being borne by his enemies; secondly, the man's life; thirdly, His own judgment; fourthly, the prophet; by all means stopping their mouths.
Then lest they should say, “But what if at that time indeed he were such an one, but now is changed?” He added also what follows; his garments, his prison, and together with these the prophecy.
Then having said, that he is greater than a prophet, He signifies also in what he is greater. And in what is he greater? In being near Him that had come. For, “I send,” says He, “my messenger before Your face;” that is, near You. For as with kings, they who ride near the chariot, these are more illustrious than the rest, just so John also appears in his course near the advent itself. See how He signified John's excellency by this also; and not even here does He stop, but adds afterwards His own suffrage as well, saying, “Verily I say unto you, among them that are born of women, there has not arisen a greater than John the Baptist.”
Now what He said is like this: “woman has not borne a greater than this man.” And His very sentence is indeed sufficient; but if you are minded to learn from facts also, consider his table, his manner of life, the height of his soul. For he so lived as though he were in heaven: and having got above the necessities of nature, he travelled as it were a new way, spending all his time in hymns and prayers, and holding intercourse with none among men, but with God alone continually. For he did not so much as see any of his fellow-servants, neither was he seen by any one of them; he fed not on milk, he enjoyed not the comfort of bed, or roof, or market, or any other of the things of men; and yet he was at once mild and earnest. Hear, for example, how considerately he reasons with his own disciples, courageously with the people of the Jews, how openly with the king. For this cause He said also, “There has not risen among them that are born of women a greater than John the Baptist.”
Source: Homilies on the Gospel of St. Matthew (New Advent)