Gospel (Lk 1,26-38) - At that time, the angel Gabriel was sent by God to a city in Galilee called Nazareth, to a virgin betrothed to a man named Joseph of the house of David. The virgin was called Mary. Entering her, he said: "Rejoice, full of grace: the Lord is with you." At these words she was very upset and wondered what sense she had in having a greeting like this. The angel said to her: «Do not be afraid, Mary, because you have found favor with God. And behold, you will conceive a son, you will give birth to him and you will call him Jesus. He will be great and will be called the Son of the Most High; the Lord God will give him the throne of David his father and he will reign over the house of Jacob forever and his kingdom will have no end." Then Mary said to the angel: "How can this be, since I do not know a man?". The angel replied to her: «The Holy Spirit will come upon you and the power of the Most High will cover you with his shadow. Therefore he who is to be born will be holy and will be called the Son of God. And behold, Elizabeth, your relative, in her old age has also conceived a son and this is the sixth month for her, who was called barren: nothing is impossible with God ». Then Mary said: «Behold the servant of the Lord: let it be done to me according to your word». And the angel walked away from her.

The commentary on the Gospel by Monsignor Vincenzo Paglia

We are on the threshold of Christmas and the Word of God brings us back to us the Lord's promise to David: «For I have not lived in a house since I brought Israel up from Egypt until today; I went wandering under a tent, in a pavilion." God did not look for a house for himself, so that his people could worship him there. God became a pilgrim with his people, ever since he heard his cry of pain in Egypt. He left his home in heaven - much richer and more comfortable than any cedar home - to descend below and free his people from slavery, accompanying them day after day in the desert of this world - living, in fact, in the tent - because his people could reach the stability of the land that he had promised them. Being under the tent is God's permanent condition. This ancient biblical page illuminates the Christmas of this difficult time: how many poor people, how many children and elderly people, sick people and refugees are abandoned, in precariousness, exactly like under an unprotected tent! But as in the time of David, as on that night in the cave outside Bethlehem, even today the Lord is in the many caves outside the houses, in the numerous places of pain and abandonment! It is there that the Lord Jesus celebrates Christmas! And it will be the Lord himself who will give a house to his people: «Perhaps you will build me a house, so that I can live in it? The Lord will make a home for you." It is the prophecy of the mystery of Christmas.
The Lord makes his people a home for everyone, a large and solid house, made of living stones. And at Christmas, when the Word becomes flesh, the Lord lays the first stone of this new spiritual building, the cornerstone, Jesus. In the customs of the time, the cornerstone had to be a stone different from the others, more resistant because it would crumble over time. It had to be chosen carefully. And God who loved the world so much sent his Son, what he held most dear. That Son who is not welcomed - like the stone that the builders rejected - God placed as the foundation of his house. This Christmas, the Lord returns to place his Son as the cornerstone of a new building. From this stone an energy of love is released which widens the walls of hearts, which widens the walls of this house of ours, it opens its doors even wider to reach wherever the poor dispersed in this society of ours are found. And we will be able to see with the eyes of the body the truth of Jesus' words: "In my Father's house there are many mansions". Wherever we go, whatever poor we meet, wherever we gather with this spirit, there the Lord is born, welcomes and consoles. The Gospel shows us Mary, the child's mother, the first of believers. In her - a little woman from Galilee - the Word becomes flesh: she opened her heart to the Word of God and became God's first home on earth.