Compendium of the 1961 Revision of the Pontificale Romanum - Part 2.3: The Dedication of a Church (Part 2)

When the bishop has come to the faldstool, he intones the hymn Veni, Creator Spiritus, which is then sung by the choir. Meanwhile, one of the servers sprinkles ashes on the floor of the church in the form of a cross, making two lines roughly a hand-span in width, from corner to corner, crossing in the middle. (If the church is very large, the lines can be can be made in separate sections for each letter of the two alphabets, Greek and Latin.)

The bishop then kneels at the faldstool, and the choir sings the Litany of the Saints; the names of the Saint to whom the church is dedicated and those whose relics are to be placed in the altar are added to it, and each sung twice. After the invocation “That Thou may deign to grant eternal rest to all the faithful departed,” the bishop rises, and takes his crook in hand; he then sings the invocations “That Thou may deign to visit this place,” and “That Thou may deign to assign therein the guarding of the Angels;” to both the choir answers “We ask Thee, hear us.”

The bishop then adds “That Thou may deign to + bless this church and altar that shall be consecrated to Thy honor, and the name of Saint N.” The choir answers as before. He adds, “That Thou may deign to + bless and sancti + fy this church and altar that shall be consecrated to Thy honor, and the name of Saint N.”, and again, “That Thou may deign to + bless, sancti + fy and conse + crate this church and altar that shall be consecrated to Thy honor, and the name of Saint N.” Each time he makes the sign of the Cross over the church and altar with his right hand, at the places marked in red; the choir answers “We ask Thee, hear us” each time, and then finishes the Litany.

When the Litany is ended, the bishop rises, and facing the main altar, says, “Oremus”, the deacon “Flectamus genua”, and the subdeacon “Levate”, after which the bishop sings the following two prayers.

May Thy mercy go before us, we beseech Thee, o Lord, and by the intercession of all Thy Saints, may Thy clement indulgence come before our voices. Through Christ our Lord. R. Amen.
Let us pray. Be Thou magnified, o Lord, our God, in Thy Saints, and appear in this temple built unto Thee, so that Thou who workest all things in the children of adoption, may always be praised in Thy inheritance. Through Christ our Lord. R. Amen.

The schola now sings the following antiphon, from second Vespers of the Dedication of a Church, with the canticle Benedictus, repeating it after each verse:

O how fearful is this place; truly this is no other than the house of God, and the gate of Heaven!

While they are singing, the bishop writes the letters of the Greek alphabet in the ashes with his crook, starting from the left of the door and going to the back of the church on the right, and then Latin alphabet on the other line, starting from the right of the door and going to the back of the church on the left.

Pope Urban VIII draws the letters of the Latin alphabet in the ashes during the consecration of St. Peter’s Basilica on November 18, 1626, the 1300th anniversary of the origin church's consecration by Pope St. Sylvester I. (Roman tapestry, ca. 1660)

In the traditional Pontifical, the bishop then blesses the so-called Gregorian water, a blessing which will be described in its own article. This water is then used to bless the altar and the walls of the church, as will also be described in a later article.

When the Litany is ended, the bishop rises and says “Let us pray.” The deacon and subdeacon do not say “Flectamus genua” and “Levate”; the bishop then says only the second of the two prayers noted above, “Be Thou magnified.” (It should be noted that as in the Missal, the prayers of the Pontifical are almost always preceded by either “Dominus vobiscum” or “Oremus. Flectamus genua. Levate.”, and “Oremus” by itself is very unusual.)