The Service of the Sacrament begins with the Preface. The Preface functions to realign our hearts to focus on the heavenly Jerusalem. To which, we will be making a pilgrimage.
Following the Preface comes the Proper Preface. The Proper Preface is a prayer of thanksgiving reflecting the season of the Church Year it is prayed in.
The Sanctus is sung after the Proper Preface. It is a song of thanksgiving composed from two Scripture passages: Isaiah 6: 2-3 and Matthew 21:9. Sanctus means “holy.” With the Sanctus, the Church on earth joins the Seraphim in Heaven, who continually sing Holy, Holy, Holy as revealed in Isaiah 6.
The second part of the Sanctus takes the words from the pilgrims, who greeted Jesus in His triumphal entry into Jerusalem. The Church on earth uses these words to greet Jesus, the One who comes in the Name of the Lord for His Holy Supper.