A biblical reflection on the virginal marriage of Mary and Joseph should not stem from their persons but from the person of Jesus, the Word incarnate and Divine Messiah. The unreproducible novelty of Christ can help in our understanding of the unusual virginal marriage of Mary and Joseph.
The marriage of Mary and Joseph testifies that God's Covenant with His people has genealogically realized itself in human history. When God chose to bless the descendants of Abraham, He committed himself to give Abraham a descent according to the normal law of nature, from generation to generation. St Matthew, the Evangelist, has given us the list of these generations (Mt 1: 1-16).
As a virginal marriage, the marriage of Mary and Joseph also testifies that the history of the Covenant has attained its summit and final term. Jesus does not marry and have children. Viewing Jesus in this way opens up a new understanding of the position of Mary and Joseph.
Their virginity is not explained by mistakenly construing that sexual relations would have had something unpure about them like a vile contamination: in the Creator's original plan everything is luminous! The true reason behind their virginity is the person of Jesus.
To become mother and father of such a Son means to have experienced union with God - in full measure and in an unrepeatable manner - the supreme aim of the Covenant
Mary, having accepted to nurture the Son of God in her virginal womb, could not desire a "more", an "again" or a "next" in other children. When she became the living abode of the Word incarnate, she attained the summit of perfection.
Already Philo of Alexandria had had an analogous intuition when he commented about why Lea, after having given birth to Judaeus, her fourth child, stopped having children (Gn 29:35). The reason is the following: Judaeus means "praise God", "he is the spirit that blesses God, continually attentive to raise up songs of thanksgiving in His honor" [1]. He is "the perfect fruit" [2].
To sing hymns to the Father of all things for giving birth is the greatest accomplishment for a new mother. This is why Lea never gave birth again - she had attained the limit of perfection [3].
Joseph, by virtue of his paternal mission, is also in contact with the presence of God become man in a tight and exceptional way. This unique and exceptional proximity with the presence of the God of the Covenant, who is Love, fills the emotional requirements of Joseph's person well beyond having sexual relations with Mary.
Saint John Paul II writes: "This "just" man, who, in the spirit of the noblest traditions of the Chosen People, loved the Virgin of Nazareth and was bound to her by a husband's love, was once again called by God to this love."
Jesus is the only child of Mary and Joseph, and this miracle cannot repeat itself. The celestial union of Mary and Joseph is an act that prevents all others.
[1] Philo of Alexandria, De Plantatione, 135
[2) Philo of Alexandria, De Somniis I,37
[3] Philo of Alexandria, De Plantatione, 135
[4] Pope John Paul II, Redemptoris Custos, #19
Bibliography:
A. Serra, Miriam, Daughter of Zion, Paris 1999
A. Serra, Joseph and Mary, the Man and the Woman of the New Era, Theotokos, 1995 #3, pp 333-363
Father Serra