At the Lamb of God the priest breaks the host into several parts. Before saying, “Behold the Lamb of God,” he “takes the host” and raises it above the paten or chalice (OM 132).
The Missal says a little more about what is expected of him at this time, however. In the section called “The Bread and Wine for Celebrating the Eucharist,” the GIRM requires that the bread “truly have the appearance of food,” and that it “be fashioned in such a way that the Priest at Mass with the people is truly able to break it into parts and distribute these to at least some of the faithful.” By doing so, he brings out “more clearly the force and importance of the sign of the unity of all in the one bread, and of the sign of charity by the fact that the one bread is distributed among the brothers and sisters” (GIRM 321).
The priest is to break the bread and distribute its parts to some of the faithful. This applies even to a three-inch host. He breaks it in order to share it. This shows unity: all are one in the one bread. And it shows charity: the priest shares his bread with others.
Many priests break and completely consume the presider’s host, however. This action lacks the symbols of unity and charity that GIRM 321 has in mind.
Some priests break the host in two, then break off a smaller part from one half, and place that part into the chalice as the rubrics direct. However, some priests then reassemble the other broken parts of the host into a circle, using thumb and forefinger to conceal the missing part they put into the chalice. They lift up to the view of the faithful what looks like an unbroken host over the chalice—as if to make them wonder, “How did he do that?” This establishes the visual image of a host floating over a chalice, so popular in Catholic iconography, but a juxtaposition of elements completely misrepresents the purpose of the breaking of bread.
A better practice is to share. Some large presider’s hosts break into twenty-four pieces, most suitable for sharing. If using a three-inch host, the presider breaks it into four pieces and then break off another small piece for the chalice. For “Behold the Lamb of God,” he raises a broken host, the quarter that he plans to consume. After receiving the host and drinking from the chalice, he then shares the other three broken pieces with some communicants. In this tiny way he symbolizes the unity and charity that the Eucharist fosters.
A priest may also consider whether the use of a separate paten and chalice for his communion interferes with the same values of unity and charity. Eating from a shared paten and drinking from a shared chalice may better express the purposes of communion.PAUL TURNER, ARS CELEBRANDI: CELEBRATING AND CONCELEBRATING MASS (COLLEGEVILLE, MN: THE LITURGICAL PRESS, 2021), 88-89.