and while he was saying that, a woman from the multitude lifted up her voice, and said unto him, Blessed is the womb that bare thee, and the breasts that nursed thee. But he said unto her, Blessed is he that heareth the word of God, and keepeth it. And while he was speaking unto the multitude, there came unto him his mother and his brethren, and sought to speak with him; and they were not able, because of the multitude; and they stood without and sent, calling him unto them. A man said unto him, Behold, thy mother and thy brethren are standing without, and seek to speak with thee. But he answered unto him that spake unto him, Who is my mother? and who are my brethren? And he beckoned with his hand, stretching it out towards his disciples, and said, Behold, my mother! and behold, my brethren! And every man that shall do the will of my Father which is in heaven is my brother, and my sister, and my mother.
Also that woman Philumena did better in persuading Apelles and the other deserters of Marcion, that Christ was indeed clothed with veritable flesh, yet without nativity, having taken it on loan from the elements. But if Marcion was afraid that belief in the flesh might also carry with it belief in nativity—there is no doubt that he who was seen to be man was naturally thought to have been born. A certain woman cried out, Blessed is the womb that bare thee, and the breasts which thou hast sucked: and how comes it that his mother and his brethren are reported standing without? But we shall consider these texts in their proper place. Certainly when he himself described himself as the Son of man, this was a claim to have been born. For the moment—so that I may defer all these matters until I come to assess the evidence of the gospel—yet which I have already established, that if he who was seen to be a man had without question to be accepted as having been born, to no purpose has conjectured that belief in nativity can be ruled out by the supposition of imaginary flesh
But as often as there is discussion of the nativity, all those who reject it as prejudging the issue concerning the verity of the flesh in Christ, claim that the Lord himself denies having been born, on the ground that he asked, Who is my mother and who are my brethren? So let Apelles too hear what answer I have already given to Marcion in that work in which I have made appeal to the Gospel which he accepts, namely that the background of that remark must be taken into consideration. Well then, in the first place no one would ever have reported to him that his mother and his brethren were standing without unless he were sure that he had a mother and brethren and that it was they whose presence he was then announcing, having either previously known them, or at least then and there made their acquaintance. This I say, in spite of the fact that the heresies have deliberately removed from the Gospel the statements that those who marvelled at his doctrine said that both Joseph the carpenter, his reputed father, and Mary his mother, and his brothers and sisters, were very well known to them. 'But,' they say, 'it was for the sake of tempting him that they announced to him the mother and the brethren whom actually he had not.' .... he answered also that other exclamation--not as denying his mother's womb and breasts, but as indicating that those are more blessed who hear the word of God. We have expounded, in terms of the truth of the Gospel as it was until Marcion and Apelles mutilated and corrupted it, those passages which these regard as their most effective armoury: and this by itself ought to have been enough to establish the fact of Christ's nativity, and thereby to prove his possession of human flesh. But inasmuch as these Apelleasts make a special point of sheltering behind the dishonour of the flesh, alleging that it was constructed for seduced souls by that fiery prince of evil and therefore is unworthy of Christ, and therefore he must needs have got him a substance from the stars, I have the task of beating them back with the aid of their own ordnance.
Blessed the womb which bore you and the breasts which suckled you. Marcion said, "They were indeed tempting him, as to whether he was born. Similarly in the case of "Behold your mother and brothers are seeking you." What was the purpose of the appearance of his body and nourishment? [Marcion] said, "That he might hide his greatness and make them believe that he was corporeal, because they were not capable of [grasping] it." Why should he have denied his birth? For if, through denying this, he wished to show them that he was not born, he would not have gone on and made himself a brother of his disciples who was born. If, from what he denied above, he refuted the idea that he was not born, then it must be believed, from what he said here, that he was born. Even if [hypothetically] kinship would have been blotted out by his denial of his mother, nevertheless through the acknowledgement of his brothers, the lineage of his paternal ancestry was made known. Moreover, even if he showed that he did not have parents because he did not recognize either his mother or his brothers, nevertheless he did say, "Why do you call me good," which was something he did not say above, namely, "Why do you call me conceived and born"? Blessed is the womb that bore you. He took blessedness from the one who bore him and gave it to those who were worshipping him. It was with Mary for a certain time, but it would be with those who worshipped him for eternity. Blessed are those who hear the word of God and keep it. (Commentary on the Harmony Gospel, McCarthy trans. p. 179 - 180)