Here we enter a new stage of Advent: having spent so much time on the Second Coming, now we look back, to remember the details of the Lord’s First Coming. We turn our focus to Mary, and hear of the angel Gabriel inviting her to take her part in the mystery of the Incarnation, the revelation of the mystery kept secret for endless ages. This mystery springs from the House of David, and so we lead into the Gospel by hearing in the first reading how David is to establish that house: He wishes to build a ‘house for the Lord’; through the prophet he is told it is not a bricks-and-mortar house that he will build, but the House which is his line. Eventually, in Mary (betrothed to Joseph) the House of David does itself become the house of the Lord, the womb wherein he has a dwelling place.