Mary gives birth to Jesus in the stable at Bethlehem. (Luke 2:1-20)
The Virgin Mary sees in the Infant that she has given to the world, a child in appearance like all other children, the very Son of God. Mary's soul was filled with an immense faith which welled up in her and surpassed the faith of all the just men of the Old Testament; this is why she recognized her God in her own Son.
This faith manifests itself externally by an act of adoration. From her very first glance at Jesus, the Virgin prostrated herself interiorly in a spirit of adoration so profound that we can never fathom its depth.
In the heart of Mary are joined in perfect harmony a creature's adoration of her God and a Mother's love for her only Son.
How inconceivably great the joy in the soul of Jesus must have been as He experienced this boundless love of His Mother! Between these two souls took place ceaseless exchanges of love which brought them into ever closer unity. O wonderful exchange: to Mary Jesus gives the greatest gifts and graces, and to Jesus Mary gives her fullest cooperation: after the union of the Divine Persons in the Blessed Trinity and the hypostatic union of the divine and human natures in the Incarnation, no more glorious or more profound union can be conceived than the union between Jesus and Mary.