7 I ask you, O faithful Christians, Was the mother of Jesus there? Answer ye, She was. Whence know you? Answer, The Gospel says it. What answer made Jesus to His mother? Answer ye, “Woman, what have I to do with you? Mine hour is not yet come.” And whence know you this? Answer, The Gospel says it. Let no man corrupt this your faith, if you desire to preserve a chaste virginity for the Bridegroom. But if it be asked of you, why He made this answer to His mother, let him declare who understands; but he who does not as yet understand, let him most firmly believe that Jesus made this answer, and made it moreover to His mother.
By this piety he will learn to understand also why Jesus answered thus, if by praying he knock at the door of truth, and do not approach it with wrangling. Only this much, while he fancies himself to know, or is ashamed because he does not know, why Jesus answered thus, let him beware lest he be constrained to believe either that the evangelist lied when he said, “The mother of Jesus was there,” or that Jesus Himself suffered for our sins by a counterfeit death and for our justification showed counterfeit scars; and that He spoke falsely in saying, “If you continue in my word, you are my disciples indeed; and you shall know the truth, and the truth shall make you free.” For if He had a false mother, false flesh, false death, false wounds in His death, false scars in His resurrection, then it will not be the truth, but rather falsehood, that shall make free those that believe in Him.
Nay, on the contrary, let falsehood yield to truth, and let all be confounded who would have themselves be accounted truth-speaking, because they endeavor to prove Christ a deceiver, and will not have it said to them, We do not believe you because you lie, when they affirm that truth itself has lied. Nevertheless, if we ask them, Whence know you that Christ said, “Woman, what have I to do with you?” they answer that they believe the Gospel. Then why do they not believe the Gospel when it says, “The mother of Jesus was there,” and, “His mother said unto Him”?
Or if the Gospel lies here, how are we to believe it there, that Jesus said this, “Woman, what have I to do with you?” Why do not those miserable men rather faithfully believe that the Lord did so answer, not to a stranger, but to His mother; and also piously seek to know why He did so answer? There is a great difference between him who says, I would know why Christ made this answer to His mother, and him who says, I know that it was not to His mother that Christ made this answer.
It is one thing to be willing to understand what is shut up, another thing to be unwilling to believe what is open. He who says, I would know why Christ thus made answer to His mother, wishes the Gospel, in which he believes, opened up to him; but he who says, I know that it was not to His mother that Christ made this answer, accuses of falsehood the very Gospel, wherein he believed that Christ did so answer.
Source: Tractates on the Gospel of John (New Advent)