6 What, then, is this, says one, which the Lord says, “Woman, what have I to do with you?” Perhaps the Lord shows us in the sequel why He said this: “Mine hour,” says He, “is not yet come.” For thus is how He says, “Woman, what have I to do with you? Mine hour is not yet come.” And we must seek to know why this was said. But first let us therefrom withstand the heretics. What says the old serpent, of old the hissing instiller of poison? What says he? That Jesus had not a woman for His mother.
Whence do you prove that? From this, says he, because Jesus said, “Woman, what have I to do with you?” Who has related this, that we should believe that Jesus said it? Who has related it? None other than John the evangelist. But the same John the evangelist said, “And the mother of Jesus was there.” For this is how he has told us: “The next day there was a marriage in Cana of Galilee, and the mother of Jesus was there. And having been invited to the marriage, Jesus had come there with His disciples.”
We have here two sayings uttered by the evangelist. “The mother of Jesus was there,” said the evangelist; and it is the same evangelist that has told us what Jesus said to His mother. And see, brethren, how he has told us that Jesus answered His mother, having said first, “His mother said unto Him,” in order that you may keep the virginity of your heart secure against the tongue of the serpent. Here we are told in the same Gospel, the record of the same evangelist, “The mother of Jesus was there,” and “His mother said unto Him.”
Who related this? John the evangelist. And what said Jesus in answer to His mother? “Woman, what have I to do with you?” Who relates this? The very same Evangelist John. O most faithful and truth-speaking evangelist, you tell me that Jesus said, “Woman, what have I to do with you?” why have you added His mother, whom He does not acknowledge? For you have said that “the mother of Jesus was there,” and that “His mother said unto Him;” why did you not rather say, Mary was there, and Mary said unto Him.
Thou tellest as these two facts, “His mother said unto Him,” and “Jesus answered her, Woman, why have I to do with you?” Why do you do this, if it be not because both are true? Now, those men are willing to believe the evangelist in the one case, when he tells us that Jesus said to His mother, “Woman, what have I to do with you?” and yet they will not believe him in the other, when he says, “The mother of Jesus was there,” and “His mother said unto Him.” But who is he that resists the serpent and holds fast the truth, whose virginity of heart is not corrupted by the subtlety of the devil?
He who believes both to be true, namely, that the mother of Jesus was there, and that Jesus made that answer to His mother. But if he does not as yet understand in what manner Jesus said, “Woman, what have I to do with you?” let him meanwhile believe that He said it, and said it, moreover, to His mother. Let him first have the piety to believe, and he will then have fruit in understanding.
Source: Tractates on the Gospel of John (New Advent)