A READING FROM THE COMMENTARY ON ISAIAH BY ST CYRIL OF ALEXANDRIA
Some of those who have translated the divine Scriptures have rendered this text: ‘Behold a young woman shall conceive.’ It seems to the Jews that the mother of the Lord should be indicated by the expression ‘young woman’ rather than be called a virgin. For they think it possible to invalidate the power of the mystery if she is called a young woman rather than a virgin. One may note their ignorance on a number of levels. First, even if the virgin is called a young woman, that does not exclude her from being a virgin. Secondly, they say that the prophet uttered these words about the wife of Ahaz, so that we should take this to refer to the birth of Hezekiah. But, my friends, one might say to them, who has called Hezekiah Emmanuel? Or how can it be proved that before he had knowledge of good and evil he rejected wickedness and chose the good? We therefore say farewell to their quibbling and welcome what is right and true, believing that in this prophecy God is indicating the Holy Virgin to us.
For in this way there will truly be a miracle and a great sign, in both its depth and its height, that has come about in accordance with the divine promise. For he who is from above, and is by nature the only-begotten Son of God the Father, emptied himself and was brought forth from a virginal womb according to the flesh, receiving his generation not from the human emission of seed but from the power and energy of the Holy Spirit. For that is why it was said to the holy Virgin by the mouth of the blessed Gabriel: The Holy Spirit will come upon you, and the power of the Most High will overshadow you. She will in consequence, he says, bear a son.
See how, in order to show that he was truly God as well as man, the prophet assigned to him attributes that were both divine and human. For when he says that he was given food suitable for infants, namely butter and honey, he is trying to assure us that he came to be in the flesh in reality. Then he teaches that although he did indeed become flesh he was nonetheless as God superior to sin, for he adds at once: For before the child knows good and evil, he will reject evil and choose the good. For men who have not yet arrived at puberty cannot discern what is vicious and what is good. This phrase therefore signifies that it belongs to the divine nature to be irrevocably fixed on the good. This is also true of Christ as, though he came into being according to the flesh through the Holy Virgin, he was holy as God both from the womb and before it, seeing that he did not lose his own prerogatives on account of his human nature. Neither did he ignore what pertains to human nature on account of the dispensation of the Incarnation, in order that he might be believed to have become like us in reality, and might sanctify this created nature of ours.
St Cyril of Alexandria, In Isaiam 1.4 (PG 70, 204A-205D), tr. Norman Russell (2000)