And there shall come forth a rod out of the root of Jesse, and a flower shall rise up out of his root.  And the spirit of the Lord shall rest upon him: the spirit of wisdom, and of understanding, the spirit of counsel, and of fortitude, the spirit of knowledge, and of godliness.  And he shall be filled with the spirit of the fear of the Lord. He shall not judge according to the sight of the eyes, nor reprove according to the hearing of the ears.  But he shall judge the poor with justice, and shall reprove with equity for the meek of the earth: land he shall strike the earth with the rod of his mouth, and with the breath of his lips he shall slay the wicked.  And justice shall be the girdle of his loins: and faith the girdle of his reins.
In a letter to Eustochium (Letter 22) Saint Jerome declares from this passage that Mary is the rod out of the root of Jesse and Christ the flower:
There shall come forth a rod out of the stem of Jesse, and a flower shall grow out of his roots. The rod is the mother of the Lord— simple, pure, unsullied; drawing no germ of life from without but fruitful in singleness like God Himself. The flower of the rod is Christ, who says of Himself:
I am the rose of Sharon and the lily of the valleys. Song of Songs 2:1 In another place He is foretold to be
a stone cut out of the mountain without hands, Daniel 2:45 a figure by which the prophet signifies that He is to be born a virgin of a virgin.
The Old Testament is filled with prophecies that point to Christ. Next Advent we will examine more. These prophecies, and the commentary of the saints upon them, are a precious inheritance for all Catholics, and during Advent it is fitting that we recall this.