In today's readings, David wants to build a house for the Lord and the Lord responds saying it will be Him who will build a house for David, a dynasty.  It is a play in words. David wanted to build a temple but God proposes to build a dynasty. Both can use the term "house". 
    For those preparing in Advent, this image of the house can still be applicable. Year after year we put out the manger scene to decorate for Christmas.  We are so used to see that Jesus is born in a manger. And we want to keep Him there! With the hay and the animals, outside in the cold because there is still no place in the inn.  As we prepare for Christmas, let's us consider this year to prepare a house for Jesus. Do not keep him outside your heart.  But like the intention of David, prepare a worthy place for him, build him a house in your life. 
     The materials (using this image of the house) to build are given in the readings.  Two major beams to build this house for the Lord are obedience and faith.  During this time of Advent is a time to set up the major beams of your house. First one, obedience to the will of God.  It is good to try to do something nice for God. But what is God really asking for you to do? Be attentive to God's will for your life in prayer.  There might be good intentions like the ones King David had, but obedience is listening well and doing God's will and not what you think should be done. The second beam to build this house is faith. This faith is demonstrated by the Virgin Mary. The angel appears to her out of nowhere and tells her, not asks her, that she will be pregnant with the Son of God. What about her plans for her youth? Mary asks important questions for  clarification but she has trust in God's design. This is what faith means, although not everything is clear in life, there is trust that God will provide.
     Overall these two beams are necessary in the life of the Christian to build a house worthy of the Lord to be born. Take this last day of Advent to ensure Jesus is born inside your house and not somewhere outside. If we build a house for the Lord,  God will build a house for us with many blessings from one generation to the next.