iclnet.org/pub/resources/text/wittenberg/mosynod/web/sup-03.html
“Martin Chemnitz’s reply to the question of whether the body and blood of Christ are present in the consecrated elements if they are laid up, enclosed, or carried about, and not used and distributed, is most appropriate: “Christ did not institute this Sacrament in such a way that, even if no one uses it, or if it is changed into something else than He Himself commanded, it nevertheless is His body and blood, but in the very words of institution He prescribed the form of that which was commanded, how it is to be observer and used, and that not only for a time but to the end of the world, 1 Cor. 11:26. And use surely does not make a Sacrament, but the Word, ordinance, and institution of Christ. And there is a difference between the essence of a Sacrament and its use. But Christ so ordered and arranged the words of institution in the form of a testament, as He wanted the Sacrament to be an act in which bread and wine are taken, blessed, or consecrated, as they say, then offered, received, eaten, and drunk. And Christ says of that which is blessed, which is offered, received, eaten and drunk: This is My body; this is My blood. Therefore when the bread is indeed blessed but neither distributed nor received, but enclosed, shown, and carried about, it is surely clear that the whole word of institution is not added to the element, for this part is lacking: He gave [it] to them and said, Take and eat. And when the word of institution is incomplete there can be no complete Sacrament. In the same way it is also no true Baptism if the Word is indeed spoken over the water, but if there is no one who is baptized” (Ministry, Word, and Sacraments, trans. Luther Poellot [St. Louis: Concordia Publishing House, 1981], p. 121).”