Cyril of Alexandria

Not to untutored or wholly ignorant souls doth Christ reveal Himself, bat shines upon and appears the rather to those who are more ready to desire to learn, and travailing with the beginning of the faith in simple words, press forward to the knowledge of what is more perfect. Such an one as this was the woman of Samaria also shown to us, giving her mind more grossly than she ought to the truly Divine ideas, but not entirely removed from the desire of understanding somewhat. …

Commentary on the Gospel of John, Book 2 ↗

Theophylact of Ohrid

When, thus, the very course of the conversation demanded it, the Lord already reveals Himself to her (the Samaritan woman). If He had said from the very beginning that Christ is I, He would not have convinced the woman, and might even have appeared somewhat arrogant and proud. But now, having little by little caused her to recall the promise concerning Christ, He already reveals Himself as well. …

Commentary on John ↗

Augustine of Hippo

Then, "The woman saith unto Him, I know that Messias will come, who is called Christ: when He then is come, He will tell us all things. Jesus saith unto her, I that speak with thee am He." She called her husband; he is made the head of the woman, and Christ is made the head of the man. Now is the woman constituted in faith, and ruled, as about to live rightly. After she heard this, "I that speak with thee am He," what further could she say, when the Lord Jesus willed to manifest Himself to the woman, to whom He had said, "Believe me?"

Tractates on John 15 ↗

Thomas Aquinas

And so Jesus says: I who speak to you am he, i.e., I am the Christ: "Wisdom goes to meet those who desire her, so she may first reveal herself to them" (Wis 6:14), and below (14:21): "I will love him, and reveal myself to him." Our Lord did not reveal himself to this woman at once because it might have seemed to her that he was speaking out of vainglory. …

Commentary on John ↗

Bonaventure

"Jesus says to her: I am he, who speaks with you." Similarly the Lord responded to the blind man below in chapter 9, when the blind man asked who the Son of God was in whom he ought to believe; the Lord responded: "You have seen him, and it is he who speaks with you." Now that faith has been declared, the preaching and conversation are concluded, because the disciples return. It is asked: since "the Lord made a shortened word upon the earth," whence is it that He drew out the Samaritan woman through so many words? …

Commentary on John, Chapter 4 ↗