There is an arrow that pierces Mary’s heart: the living and active Word of God that cuts more keenly than any two-edged sword. Of this our Savior said: I have not come to send peace but the sword. A polished arrow, too, is that special love of Christ, which not only pierced Mary’s soul but penetrated through and through, so that even the tiniest space in her virginal breast was permeated by love. Therefore she would love with her whole heart, her whole soul and her whole strength, and be full of grace. It transpierced her that it might thus come down even to us; and of that fullness we might all receive. She would become the mother of that love whose father is God, who is love. When that love was brought to birth, he would place his tent in the sun that the Scripture might be fulfilled: I will make you the Light of the nations so that you may be my salvation to the ends of the earth.
This was it fulfilled through Mary, who brought forth in visible flesh him who she conceived invisibly, neither from the flesh nor by the flesh. In the process she experienced in her whole being a wound of love that was mighty and sweet. And I would reckon myself happy if at rare moments I felt at least the prick of the point of that sword. Even bearing only love’s slightest wound, I could still say, I am wounded with love. How I long not only to be wounded in this manner but to be assailed again and again till the color and heart of that flesh that wars against the spirit is overcome.
from Sermon 29 On the Song of Songs by Bernard of Clairvaux, CF 7, pp 109-110