Alexander of Alexandria : And in one Lord Jesus Christ, the only-begotten Son of God; not begotten of things which are not, but of Him who is the Father; not in a corporeal manner, by excision or division as Sabellius and Valentinus thought, but in a certain inexplicable and unspeakable manner, according to the words of the prophet cited above: "Who shall declare His generation?" Since that His subsistence no nature which is begotten can investigate, even as the Father can be investigated by none; because that the nature of rational beings cannot receive the knowledge of His divine generation by the Father. But men who are moved by the Spirit of truth, have no need to learn these things from me, for in our ears are sounding the words before uttered by Christ on this very thing, "No man knoweth the Father, save the Son; and no man knoweth who the Son is, save the Father." — EPISTLES ON THE ARIAN HERESY 1:12 Athanasius of Alexandria : For he it is who proceeded from a virgin and appeared as man on the earth and whose generation after the flesh cannot be declared. For there is none who can tell his father after the flesh, his body not being of a man but of a virgin alone. Thus, no one can declare the corporeal generation of the Savior from a man in the same way as one can draw up a genealogy of David and Moses and of all the patriarchs. — On the Incarnation of the Word 37 Augustine of Hippo : The Son of God, who is also the Son of man, our Lord Jesus Christ, born of the Father without mother, created every single day; born of his mother without father, he consecrated this particular day [Christmas Day]; invisible in his divine birth, visible in his human one, in each of them wonderful. Thus it is difficult to judge about which of the two the prophet is more likely to have prophesied, "Who shall tell the tale of his begetting?"—whether of that one in which, never not born, he has the Father co-eternal with himself; or of this one in which, born at a particular time, he had already made the mother of whom he would be made; whether of that one where he was always born, since he always was. Who, after all, will tell the tale of how light was born from light, and they were both one light; how God was born from God, and the number of gods did not increase? — SERMON 195:1 Augustine of Hippo : If you think this to be referred to the human generation by which he was born of a virgin, look into yourself and ask your soul whether the prophet would dare to declare the divine generation if words failed him for the human one. — LETTER 242 Augustine of Hippo : To sum up, Christ was born both of a Father and of a mother; both without a father and without a mother; of a Father as God, of a mother as man; without a mother as God, without a Father as man.… "Who will recount his begetting," whether that one without time or this one without seed; that one without beginning or this one without precedent; that one which never was not, or this one which never was before or after that one which has no end, or this one which has its beginning in its end? — SERMON 184:3 Cyril of Jerusalem : This sheep is equally called shepherd and says "I am the good Shepherd." By his manhood he is sheep; by his divine loving-kindness he is shepherd. — Catechetical Lecture 10:3 Gaius Marius Victorinus : Those who do not understand the manner of begetting may mislead you when they say, "Who can speak of the birth of the Lord?" First, "who" or still more "no one" does indeed seem to signify men. Only the Holy Spirit can grasp or explain this manner of begetting. That is why we ourselves with the permission of God the Father and of Jesus Christ our Lord have set it forth. Certainly it is not a hopeless enterprise, but we have described it as by a miracle. Next, supposing that the manner of begetting is unknown, we speak of substance when we say that the Father and Son are of the same essence (homoousios). — ON THE NECESSITY OF ACCEPTING HOMOOUSION 4 Jerome : He was taken away by distress and judgment. Who can describe his generation? For he was cut off from the land of the living; because of the transgression of my people he was struck down. LXX: In his humility his judgment was taken away. Who will declare his generation, for his life is taken from the earth? He was led away to death because of the iniquities of my people. And what follows: He was taken away from distress and judgment; or as the Septuagint translated, in his humility his judgment was taken away, it signifies that he, having conquered, ascended from tribulation and judgment to the Father; or that the judge of all will not find truth in judgment; but that he was condemned without any fault, through the sedition of the Jews and the voice of Pilate. Therefore, the Prophet marvels that God has delivered himself to the passion of all. About what Paul is speaking: For if they had believed, they would never have crucified the Lord of glory (1 Cor. 2:8). It follows: Who will declare His generation? This is understood in two ways: either it is to be understood about His divinity, that the mysteries of His divine birth are impossible to know; about which He Himself speaks in the Proverbs: Before all the hills He brought me forth (Prov. 8:25); according to what we read elsewhere: For who has known the mind of the Lord? Or who has been His counselor? (Rom. 11:34)? That is, no man; or about the birth of the Virgin, which can hardly be explained. Finally, when it was said to Mary by the Angel: You shall conceive and bear a son, she responded: How shall this be, since I do not know man? To which the Angel again said: The Holy Spirit will come upon you, and the power of the Most High will overshadow you (Luke 1:31, 34, 35), so that the mysteries of this birth may be attributed either to the Angel or to the Evangelist alone. Whose narrator is very rare, according to that: Who is wise, and will understand these things: prudent, and will know them? (Hosea XIV, 10) But if a wise reader responds in silent thought: And how is it written: No one knows the Son except the Father: and no one knows the Father except the Son, and to whom the Son wills to reveal? And he who knows the Father and the Son, surely he can explain the mystery of their generation. Let him hear that knowing something and speaking it are different, because often we cannot explain with words what we conceive in the mind. Therefore, the mystery of the divine nativity in the body can be known by the saints through faith more than it can be expressed in words. Otherwise, even the Apostle, who was caught up to the third heaven and into paradise, heard words that human language cannot utter (2 Corinthians 12). But the Spirit intercedes for us with ineffable groanings. Therefore, the life of the one whose generation can be narrated by no one or by few has been taken away from the earth, so that he would live not on earth, but in heaven. Whether he was cut off from the land of the living, in order to fulfill what was written in the Apocalypse of John: I am the first and the last: I am he that liveth, and was dead; and behold, I am alive for evermore (Rev. 1:17-18); so that after the life he lived on earth, dead to the world, he would live in eternity. And the statement is connected, He struck them for the wickedness of my people; or, according to the Septuagint, he was led to death because of the iniquities of my people, has a twofold meaning. For either he struck down persecutors and wicked people of his own people with his death, or on account of the greatness of the sins of the people, whom he always held as his own, he was led to death in order to call them back to life by his death. — Commentary on Isaiah Leo the Great : The birth of our Lord and Savior, whether that of his divinity from the Father or that of his flesh from his mother, surpasses the power of human eloquence. As a result, the saying ("Who will recount his generation?") may rightly be referred to either. — SERMON 30:1