From: Luke 1:39-45
 In those days Mary arose and went with haste into the hill country, to a city of Judah,  and she entered the house of Zechariah and greeted Elizabeth.  And when Elizabeth heard the greeting of Mary, the babe leaped in her womb; and Elizabeth was filled with the Holy Spirit  and she exclaimed with a loud cry, "Blessed are you among women, and blessed is the fruit of your womb!  And why is this granted me, that the mother of my Lord should come to me?  For behold, when the voice of your greeting came to my ears, the babe in my womb leaped for joy.  And blessed is she who believed that there would be a fulfillment of what was spoken to her from the Lord."
39-56. We contemplate this episode of our Lady's visit to her cousin St. Elizabeth in the Second Joyful Mystery of the Rosary: "Joyfully keep Joseph and Mary company...and you will hear the traditions of the House of David.... We walk in haste towards the mountains, to a town of the tribe of Judah (Luke 1:39).
"We arrive. It is the house where John the Baptist is to be born. Elizabeth gratefully hails the Mother of her Redeemer: Blessed are you among women, and blessed is the fruit of your womb. Why should I be honored with a visit from the mother of my Lord? (Luke 1:42-43).
"The unborn Baptist quivers...(Luke 1:41). Mary's humility pours forth in the "Magnificat".... And you and I, who are proud--who were proud--promise to be humble" ([St] J. Escriva, "Holy Rosary").
39. On learning from the angel that her cousin St. Elizabeth is soon to give birth and is in need of support, our Lady in her charity hastens to her aid. She has no regard for the difficulties this involves. Although we do not know where exactly Elizabeth was living (it is now thought to be Ain Karim), it certainly meant a journey into the hill country which at that time would have taken four days.
From Mary's visit to Elizabeth Christians should learn to be caring people. "If we have this filial contact with Mary, we won't be able to think just about ourselves and our problems. Selfish personal problems will find no place in our mind" ([St] J. Escriva, "Christ Is Passing By," 145).
42. St. Bede comments that Elizabeth blesses Mary using the same words as the archangel "to show that she should be honored by angels and by men and why she should indeed be revered above all other women" ("In Lucae Evangelium Expositio, in loc.").
When we say the "Hail Mary" we repeat these divine greetings, "rejoicing with Mary at her dignity as Mother of God and praising the Lord, thanking Him for having given us Jesus Christ through Mary" ("St. Pius X Catechism", 333).
43. Elizabeth is moved by the Holy Spirit to call Mary "the mother of my Lord", thereby showing that Mary is the Mother of God.
44. Although he was conceived in sin--original sin--like other men, St. John the Baptist was born sinless because he was sanctified in his mother's womb by the presence of Jesus Christ (then in Mary's womb) and of the Blessed Virgin. On receiving this grace of God St. John rejoices by leaping with joy in his mother's womb--thereby fulfilling the archangel's prophecy (cf. Luke 1:15).
St. John Chrysostom comments on this scene of the Gospel: "See how new and how wonderful this mystery is. He has not yet left the womb but he speaks by leaping; he is not yet allowed to cry out but he makes himself heard by his actions [...]; he has not yet seen the light but he points out the Sun; he has not yet been born and he is keen to act as Precursor. The Lord is present, so he cannot contain himself or wait for nature to run its course: he wants to break out of the prison of his mother's womb and he makes sure he witnesses to the fact that the Savior is about to come" ("Sermo Apud Metaphr., Mense Julio").
45. Joining the chorus of all future generations, Elizabeth, moved by the Holy Spirit, declares the Lord's Mother to be blessed and praises her faith. No one ever had faith to compare with Mary's; she is the model of the attitude a creature should have towards its Creator--complete submission, total attachment. Through her faith, Mary is the instrument chosen by God to bring about the Redemption; as Mediatrix of all graces, she is associated with the redemptive work of her Son: "This union of the Mother with the Son in the work of salvation is made manifest from the time of Christ's virginal conception up to His death; first when Mary, arising in haste to go to visit Elizabeth, is greeted by her as blessed because of her belief in the promise of salvation and the Precursor leaps with joy in the womb of his mother [...]. The Blessed Virgin advanced in her pilgrimage of faith and faithfully persevered in her union with her Son unto the cross, where she stood (cf. John 19:25), in keeping with the Divine Plan, enduring with her only-begotten Son the intensity of His suffering, associating herself with His sacrifice in her mother's heart, and lovingly consenting to the immolation of this Victim which was born of her" (Vatican II, "Lumen Gentium", 57f).
The new Latin text gives a literal rendering of the original Greek when it says "quae credidit" (RSV "she who has believed") as opposed to the Vulgate "quae credidisti" ("you who have believed") which gave more of the sense than a literal rendering.
Source: "The Navarre Bible: Text and Commentaries". Biblical text taken from the Revised Standard Version and New Vulgate. Commentaries made by members of the Faculty of Theology of the University of Navarre, Spain. Published by Four Courts Press, Kill Lane, Blackrock, Co. Dublin, Ireland. Reprinted with permission from Four Courts Press and Scepter Publishers, the U.S. publisher.