Catechesis: the Eucharist

Indeed, in the administration of the Holy Supper the Words of Institution are to be clearly and plainly spoken or sung publicly in the congregation, and in no case to be omitted.... But this “blessing” or the recitation of the Words of Institution of Christ by itself does not make a valid sacrament if the entire action of the Supper, as Christ administered it, is not observed (as, for example, when the consecrated bread is not distributed, received, and eaten, but is locked up, made into a sacrifice, or carried around in procession). On the contrary, Christ’s command, “Do this,” must be observed without division or confusion.—FC SD VII:79, 83