How become they one flesh? As if you should take away the purest part of gold, and mingle it with other gold; so in truth here also the woman as it were receiving the richest part fused by pleasure, nourishes it and cherishes it, and withal contributing her own share, restores it back a Man. And the child is a sort of bridge, so that the three become one flesh, the child connecting, on either side, each to other. For like as two cities, which a river divides throughout, become one, if a bridge connect them on both sides, so is it in this case; and yet more, when the very bridge in this case is formed of the substance of each. As the body and the head are one body; for they are divided by the neck; but not divided more than connected, for it, lying between them brings together each with the other. And it is the same as if a chorus that had been severed should, by taking one part of itself from this quarter, and the other again from the right, make one; or as these when come into close rank, and extending hands, become one; for the hands extended admit not of their being two. Therefore to wit He said with accuracy of expression, not “they shall be one flesh” but joined together “into one flesh” (Genesis 2:2, Septuagint) namely, that of the child. What then? When there is no child, will they not be two? Nay, for their coming together has this effect, it diffuses and commingles the bodies of both. And as one who has cast ointment into oil, has made the whole one; so in truth is it also here.
I know that many are ashamed at what is said, and the cause of this is what I spoke of, your own lasciviousness, and unchasteness. The fact of marriages being thus performed [with elaborate, lascivious and expensive festivities, etc.], thus depraved, has gained the thing an ill name: for “marriage is honorable, and the bed undefiled.” (Hebrews 13:4) Why are you ashamed of the honorable, why do you blush at the undefiled? This is for heretics, this is for such as introduce harlots there. For this cause I am desirous of having it thoroughly purified, so as to bring it back again to its proper nobleness, so as to stop the mouths of the heretics. The gift of God is insulted, the root of our generation… [For if you] art ashamed at these, surely then you condemn God who has thus decreed.
Thanks to Salt of the Earth