First, my apology for being late with this. I was away on retreat from last Sunday evening until Friday evening. While I was away, though, I worked on this post, reviewing the scriptures and considering the commentaries. Even if you can't look this over in preparation for attending Mass, I hope it will be worth reading.
Second, a word about the dogma of the Assumption. Pope Pius XII declared in 1950, "By the authority of our Lord Jesus Christ, of the Blessed Apostles Peter and Paul, and by our own authority, we pronounce, declare, and define it to be a divinely revealed dogma: that the Immaculate Mother of God, the ever Virgin Mary, having completed the course of her earthly life, was assumed body and soul into heavenly glory." Here is the full text of the Apostolic Constitution defining the dogma. As you can see, this was not a novelty, but something that had been generally believed for centuries.
Finally, a word about scripture. It is common to see in various persons, things, and events of the Old Testaments prefigurings of persons, events, or things in the New Testament. These are called "types." They illustrate the New Testament reality. To give one example. the manna of the Old Testament is a type of the Eucharistic bread, the bod of Jesus given for the life of the world. Another type is Isaac, carrying the wood for him to be sacrificed, just as Jesus bore the wood of the cross. While the scriptures do not say in so many words, "Mary was assumed into heaven," Old Testament types, together with various passages in the New Testament provide a basis for those who ponder these things in their hearts to see that Mary did not undergo the corruption of the tomb.
Like other solemnities, the Assumption has two Mass formularies: one for the vigil, and one for the day itself. Because there are connections between them, I'll consider them together.
The first reading of the vigil —1 Chronicles 15:3-4, 15-16; 16:1-2 — gives the essentials of King David's bringing the Ark of the Covenant to the tent he had prepared for it in Jerusalem. The Ark is seen as a type of Mary, since she carried Jesus in her womb, just as the Ark contained three things: the tablets of the commandments, corresponding to Jesus, the Word of God; some manna, corresponding to Jesus, the Bread of Life; Moses' rod with which he parted the Red Sea and brought water from the rock, corresponding to Jesus, the giver of Baptism. So the bringing of the Ark to Jerusalem prefigures the bringing of Mary to God's eternal dwelling place.
Psalm 132:6-7, 9-10, 13-14, with a response from verse 8, has us reflect on the bringing of the Ark to Jerusalem, the dwelling place of the Lord.
On the day itself, the first reading — Revelation 11:19a; 12:1-6a, 10ab — opens with a vision of the Ark of the Covenant in God's temple in heaven. Again, the Ark is seen as a type of Mary.
Another vision follows, that of a glorious, celestial, crowned woman who is about to give birth. The description of her child — in language reminiscent of Psalm 2:8-9 — makes it clear that he is the Messiah. He is snatched up into heaven at his Ascension. If the child is Jesus, then in a literal sense, the woman of the vision must be Mary. But the birth of Jesus and his Ascension do not end the dragon's (Satan's) attack on the woman. She must flee to the desert, where God provides for her. It is generally understood that here the woman comes to represent the Church, under persecution. But, as Jesus promised, the gates of hell will not prevail against it.
In response, Psalm 45:10, 11, 12, 16 invites us to reflect on Mary as God's queen. The woman of Revelation bears a crown; Mary' is mother of the Son of God. So we see this queen as a type of Mary, now in heaven with God.
The second reading of each Mass is from 1st Corinthians, chapter 15 — 15:54b-57 on the vigil, and 15:20-27 for the day. Christ is the conqueror of sin and death. Christ makes bodily resurrection and immortality available to all his people. Therefore Mary's Assumption differs only in timing from what awaits all other Christians at the end of time.
The gospel of the vigil — Luke 11:27-28, reminds us that being the mother of Jesus would have been of no benefit to Mary if she hadn't heard the word of God and observed it. But she did hear and keep it, from the Annunciation, to the visit of the Magi and the finding of Jesus in the temple: occasions after which she pondered the meaning of them in her heart. And so after the Ascension, the Apostles persevered in prayer with her. We too are blessed if, like Mary, we hear God's word and observe it.
In the Mass of the day, the gospel — Luke 1:39-56 — presents words in praise of Mary similar to those from the previous evening. "Blessed are you among women, and blessed is the fruit of your womb." This also reminds us of Gabriel's greeting to Mary, "Hail, ful of grace." On this occasion, the one who recognizes Mary's blessedness is Elizabeth, the mother of John the Baptist. She has not heard Jesus teach, but John's leap in her womb tells her that Mary's unborn child is the Lord. And she goes on to recognize what Jesus pointed out to the other woman: that Mary's blessedness is tied to believing the word of the Lord.
For her part. Mary recognizes that her blessedness, and its recognition through all generations, is God's work, not her own doing. It is one element in his saving work throughout history.
Today, I came across a link to this post. It is fascinating. There is something called microchimerism. "In human fetomaternal microchimerism (or “fetal cell microchimerism”), every child leaves within his mother a microscopic bit of himself — every pregnancy, brought to delivery or not, leaves a small amount of its own cells within the body of the mother — and those cells remain within her forever." So Mary carried some cells of Jesus in her body. Since Jesus' cells couldn't undergo corruption, Mary's body housing them couldn't. It's not a long piece, and I suggest you read the whole thing.
Happy Feast Day.