In part my intent has simply been to promote an awareness that these figures are to be found in our liturgical books. But as well it has been my intent to indirectly refer back to a point that has been made here before (see for example: Old Testament Righteous: Liturgical Feasts and References, Icons and Mosaics, and the Importance of Biblical Typology, Sept. 2009), namely that there is great profit to be found in having a greater familiarity with the great men and women of the Old Testament and the events of Old Testament generally for it brings with it a knowledge of salvation history, of biblical typology, can be a key to understanding some of our liturgical symbols and texts, and further provides us with theological and spiritual insight generally.
As the Catechism of the Catholic Church teaches us in paragraph 129:
Christians therefore read the Old Testament in the light of Christ crucified and risen. Such typological reading discloses the inexhaustible content of the Old Testament; but it must not make us forget that the Old Testament retains its own intrinsic value as Revelation reaffirmed by our Lord himself. Besides, the New Testament has to be read in the light of the Old. Early Christian catechesis made constant use of the Old Testament. As an old saying put it, the New Testament lies hidden in the Old and the Old Testament is unveiled in the New.
With that, we come to today, December 29th, in which the Roman Martyrology remembers St. David, King and Prophet, "the shepherd who prays for his people and prays in their name" (CCC 2579), a "type" of Jesus Christ. Read more about King David here.