The Byzantine liturgical calendar includes the prophets in its commemorations because they foretell the coming of the Messiah, as the Kontakion states for today. (The Latin Church has the prophets in the Martyrology but does often feasts.) As a liturgical note, kontakion is a poetic text tied to the celebration at hand, or of a particular saint recalled during the Liturgy, most often sung by the deacon or some designated person following the proclamation of the gospel.
the world the coming forth of God from the south, from the Virgin. Standing on
the divine watch, you received a report from the radiant angel: “You proclaimed
the Resurrection of Christ to the world!” Therefore in gladness we cry out to
you: “Rejoice, splendid adornment of the prophets!”