Tertullian

“ But it could not possibly have had blood for transformation into milk, unless it possessed the causes of blood also, that is to say, the severance (by birth) [17] of its own flesh from the mother’s womb. Now it is easy to see what was the novelty of Christ’s being born of a virgin. It was simply this, that (He was born) of a virgin in the real manner which we have indicated, in order that our regeneration might have virginal purity,—spiritually cleansed from all pollutions through Christ, who was Himself a virgin, even in the flesh, in that He was born of a virgin’s flesh. ”

“ Even when one strange matter amalgamates with another, it becomes so entirely incorporated [14] with that with which it amalgamates, that when it is drawn off from it, it carries with it some part of the body from which it is torn, as if in consequence of the severance of the union and growth which the constituent pieces had communicated to each other. ”

“ You say that He was born through [2] a virgin, not of [3] a virgin, and in a womb, not of a womb, because the angel in the dream said to Joseph, “That which is born in her” (not of her) “is of the Holy Ghost.” ”