29 These are excellent suggestions of the narratives: but the Jews still contradict, and do not yield to the statements concerning the rod, unless they may be persuaded by similar strange and supernatural births. Question them, therefore, in this way: of whom in the beginning was Eve begotten? What mother conceived her the motherless? But the Scripture says that she was born out of Adam's side. Is Eve then born out of a man's side without a mother, and is a child not to be born without a father, of a virgin's womb? This debt of gratitude was due to men from womankind: for Eve was begotten of Adam, and not conceived of a mother, but as it were brought forth of man alone. Mary, therefore, paid the debt, of gratitude, when not by man but of herself alone in an immaculate way she conceived of the Holy Ghost by the power of God.
Source: Catechetical Lectures (New Advent)