Ambrose of Milan : If the union of Adam and Eve is a great mystery in Christ and in the church, it is certain that as Eve was bone of the bones of her husband and flesh of his flesh, we also are members of Christ's body, bones of his bones and flesh of his flesh. — Letters Aphrahat the Persian Sage : From the law we heard: "Therefore a man leaves his father and his mother and cleaves to his wife, and they will become one flesh." This is a great and sublime prophecy. Who actually leaves his father and mother when he takes a wife? This is the meaning of the words: man in his original condition loved and worshiped God, his father, and the Holy Spirit, his mother. He did not have any other love. In order to take a wife, man leaves his mother and father, those whom I mentioned above. His mind is thereby diverted by this world. His soul and mind are driven away from God and drawn into this world that he adores and loves "as a man loves the wife of his youth." The love for this wife is different from the love for the father and the mother. Scripture adds, "They will become one flesh." It is true that as some men make one flesh and soul with their wife, and their mind and thoughts are driven away from their father and mother, so those who never take a wife and stay alone may have a single spirit and mind with their father. — DEMONSTRATIONS 18.10-11 Augustine of Hippo : Scripture said, "A man will leave father and mother, and he will cling to his wife, and they will be two in one flesh." This is what generally happens in the human race. There is no other way to view its plain, historical sense. But more so, this is all prophecy, and the apostle reminds us of this when he says, "For this reason a man will leave his father and mother and he will cling to his wife, and they will be two in one flesh. This is a great mystery; I mean in Christ and in the church." — TWO BOOKS ON GENESIS AGAINST THE MANICHAEANS 2.13.19 Bede : Wherefore a man shall leave his father and mother, and shall cleave to his wife, and they shall be two in one flesh. Though the Scripture itself testifies that these words were first said by man, yet the Lord in the Gospel declared that God said them. For He said: Have you not read that He who made them from the beginning made them male and female, and said: For this cause shall a man leave his father and mother and shall cleave to his wife, and they shall be two in one flesh (Matt. XIX, 4), that we might understand from this that, on account of the ecstasy which preceded in Adam, he could have said this divinely as a prophet. Therefore, if Christ adhered to the Church so they would be two in one flesh, how did He leave the Father, how the mother? He left the Father because, being in the form of God, He did not consider it robbery to be equal with God but emptied Himself, taking the form of a servant (Phil. II, 6). This means He left the Father, not because He deserted and departed from the Father, but because He did not appear to men in that form in which He is equal to the Father; just as He left the mother by leaving the Synagogue of the Jews, from whom He was born according to the flesh, and adhering to the Church, which He gathered from all nations, so that in the peace of the New Testament they might be two in one flesh: because, being God with the Father through whom we were made, He became a partaker with us through the flesh, so that we could be the body of that head. — Commentary on Genesis (Hexaemeron) Ephrem the Syrian : He said "a man shall leave his father and his mother and attach himself to his wife " [ Gen. 2:24 ] so that they might be united and the two of them become one, without division, as they were originally. Ephrem the Syrian : Then Adam said, "Let the man leave his father and his mother and cling to his wife so that they might be joined and the two might become one" without division as they were from the beginning. — COMMENTARY ON Genesis 2.13.3 John Chrysostom : Where, tell me, did these things come from for him to utter? From what source did he gain knowledge of future events and the fact that the race of human beings should grow into a vast number? Whence, after all, did he come to know that there would be intercourse between man and woman? I mean, the consummation of that intercourse occurred after the fall; up till that time they were living like angels in paradise and so were not burning with desire, not assaulted by other passions, not subject to the needs of nature; on the contrary, they were created incorruptible and immortal, and on that account at any rate they had no need to wear clothes.… So from what source, tell me, did these things come for him to utter? Surely it's obvious that before his disobedience he had a share in prophetic grace and saw everything through the eyes of the Spirit. — HOMILIES ON Genesis 15-16 Origen of Alexandria : Indeed, in the Scriptures two are often spoken of as one. What passages of Scripture are these? Adam is one man, his wife is another. Adam is distinct from the woman, and the wife is distinct from the man. Yet in the account of the creation of the world it is straightway said that the two were one: "and the two shall be one flesh." Consequently it is possible sometimes for two fleshes to be one. Note, however, that in the case of Adam and Eve it is not said that these two are to become one spirit, nor that they are to become one soul, but: the two shall be one flesh. And again, the Apostle says that the righteous man is one with Christ, but he is distinct from Christ: "And he who cleaves to the Lord is one spirit with Him." … In turn, our Savior and Lord, in relation to the Father and God of all, is neither one flesh nor one spirit, but something higher than one flesh, than one spirit — one God. When people are united with one another, the fitting word is flesh. When the righteous man cleaves to Christ, the fitting word is spirit. But when Christ is one with the Father, the fitting word is neither flesh nor spirit, but the more worthy one — God. From this we also understand the saying: "I and the Father are one." — DIALOGUE WITH HERACLIDES Philoxenus of Mabbug : For when the soul hath intercourse with the body, this intercourse is adultery and fornication; but if the body be united unto the soul in one agreement, and be raised above from below in a right union, it is the intercourse which is according unto the law, which is implanted naturally in the person of each one of us by the Creator. For behold the connection which men have with women according to nature was ordained by the command of the Creator at the beginning, and when it taketh place according to the will of the Creator, it is called lawful connection; but if it be performed in any other way it is called adultery and fornication, and as in a mystery this parable is depicted in reference unto the soul and body. For if the soul hath intercourse with the body it is fornication, but if the body hath intercourse with the soul, it is an union according to the law, and towards this meaning also inclineth the words of the Book which saith, "A man shall leave his father and his mother, and cleave unto his wife." Now it doth not say concerning the woman that she shall leave her parents, and cleave unto the man, although according to the custom of the world women do actually leave their natural parents, and cleave unto their husbands, and it appeareth that, according to custom, the opposite of the words of the Book are done in nature; so therefore that which is said of the man is a parable which is based on the body, which shall leave everything in which it hath gratification, and shall be united unto the soul. For if the Book had said, "A woman shall leave her parents, and cleave unto a man," it would have taught that the soul should have intercourse with the body, but now that it hath spoken concerning the man, "He shall leave his parents and be united unto his wife," the words indicate to us a mystery of doctrine, and exhort the body to deny itself its pleasures, and to hate its lusts, and to have connection with the soul in all good things. — 13 Ascetic Discourses, Discourse 12 -- First Discourse on Fornication Tertullian : There were more ribs in Adam, and hands that knew no weariness in God; but not more wives in the eye of God. And accordingly the man of God, Adam, and the woman of God, Eve, discharging mutually (the duties of) one marriage, sanctioned for mankind a type by (the considerations of) the authoritative precedent of their origin and the primal will of God. Finally, "there shall be," said He, "two in one flesh," not three nor four. On any other hypothesis, there would no longer be "one flesh," nor "two (joined) into one flesh." These will be so, if the conjunction and the growing together in unity take place once for all. If, however, (it take place) a second time, or oftener, immediately (the flesh) ceases to be "one," and there will not be "two (joined) into one flesh," but plainly one rib (divided) into more. But when the apostle interprets, "The two shall be (joined) into one flesh" of the Church and Christ, according to the spiritual nuptials of the Church and Christ (for Christ is one, and one is His Church), we are bound to recognise a duplication and additional enforcement for us of the law of unity of marriage, not only in accordance with the foundation of our race, but in accordance with the sacrament of Christ. From one marriage do we derive our origin in each case; carnally in Adam, spiritually in Christ. The two births combine in laying down one prescriptive rule of monogamy. In regard of each of the two, is he degenerate who transgresses the limit of monogamy. Plurality of marriage began with an accursed man. Lamech was the first who, by marrying himself to two women, caused three to be (joined) "into one flesh." [Exortation to Chastity 5] — On Exhortation to Chastity