John Chrysostom

But Christ knowing the purpose of John, did not say, I am He; for this would again have offended the hearers, although this was what it naturally followed for Him to say, but He leaves them to learn it from His acts. For it saith, "when these were come to Him, then He cured many." And yet what congruity was there, that being asked, "Art thou He," He should say nothing to that, but should presently cure them that were sick; unless it had been His mind to establish this which I have mentioned? …

Homily on the Gospel of Matthew 36 ↗

Theophylact of Ohrid

He did not say, "Declare unto John that I am He that cometh." But knowing that John had sent his disciples to see the miracles, He said, "Tell John what you see, and certainly he will use that opportunity to bear witness more fully to you concerning Me." By the words "the poor have the good tidings" understand either those preaching the Gospel, that is, the apostles, who were poor fishermen and despised as common lowly people, or those listening to the Gospel and hearing of the eternal good things.

Commentary on Matthew ↗

Jerome

And Jesus answered and said to them, 'Go and tell John what you hear and see: The blind receive sight, the lame walk, the lepers are cleansed, the deaf hear, the dead are raised up.' John had asked through his disciples: 'Are You the Coming One, or do we look for another?' Jesus shows the signs, not responding to what had been asked, but to the stumbling block of the messengers: 'Go and tell John the things which you hear and see: The blind see and the lame walk; the lepers are cleansed and the deaf hear; the dead are …

Commentary on Matthew ↗

Gregory the Dialogist

Hence also, when the Lord was asked, after enumerating the miracles of his power, he immediately responded about the humility of his death, saying: "The blind see, the lame walk, lepers are cleansed, the deaf hear, the dead rise, the poor have the gospel preached to them, and blessed is he who is not scandalized in me." Seeing so many signs and such great powers, no one could be scandalized, but only marvel.

Forty Gospel Homilies, Homily 6 ↗

Thomas Aquinas

And Jesus answered them. Here Christ's answer is given. John and many disciples, as John says (c. 4). Therefore, there was a dispute among them, because they saw Christ's works and preferred him to John. But seeing John's abstinence, they prefer him to Christ. Hence, first he proposes the question; secondly, he commends John (v. 10). In regard to the first he answers in terms of his coming and Passion. The time will come, when God will suffer and many will be scandalized, because "to the Jews a scandal" (1 Cor 1:23). …

Commentary on Matthew ↗