Zwingli said that it is a disgrace that we adhere to such a serious article, teach and champion it, all without being able or willing to cite Scripture on this point.
Whereupon Luther lifted the velvet tablecloth and showed him the quote, “This is my body,” which he had written with the chalk for himself, and said, “Here is our Scripture. You still haven’t taken it away from us, as you claimed you would. We need no other.”
Zwingli asked whether he had no other additional Scripture, argument, or proof.
Luther answered, “I do indeed have others, as you will hear, if you succeed in taking this one away from me. For as long as I have this certain word of God, which no one can wrestle from me, I do not need to let go of it and look for another. Topple this one, and you will hear the other arguments that I have."
Zwingli and Oecolampadius introduced this evidence from Holy Scripture and no more. Rather, they continued and wanted to investigate according to reason, how a body could be in many places or transcend place. Luther, however, did not want to permit this, saying that “reason, philosophy, and mathematics have no place here, for if we conclude thusly that a body can only be in one place, it would only prove that according to the common course of nature, the body can only be in one place. It would never be claimed, however, that God’s almighty word has no other power beyond common nature, so that it would prove nothing here, etc.” And he offered, if they were not convinced, that he would discuss the matter with them later [literally, outside of these dealings], an hour or two, a day or two, or even a whole month, etc. They asked where God had ever had one body that was not present or contained in a particular place, to which Luther replied, “God holds the largest body of all, which must include all other bodies, namely, the entire world, without a fixed place. Thus the world has no place in which it exists.” On this point they were [then] all still.
As a result they did not present anything further from Scripture, which surprised us very much, but we had no doubt it was because they knew how they would be answered and that it would lead to more embarrassment than their silence. For if they had come with the Scripture, “He sits to the right hand of the Father” [Mark 16:19] and others with which they have blinded and misled the common man, they would have been beautifully [in an ironic sense] received, for then we would have been consulted and would have entangled them in their own answers. It would have been of no use to them, but they anticipated this and admitted themselves that the right hand of God is not a particular place or location but rather the omnipotence of God, from which it can be deduced how conscientiously they were negotiating.
Sunday morning and afternoon, Zwingli and Oecolampadius presented passages from the [Church] Fathers, namely one from Fulgentius and several from Saint Augustine, with which they tried to prove that a body must be in a particular place and that the bread in communion is a symbol of the body and blood of Christ. We listened to them talk about it for the whole day, while they searched for, read, and translated the passages [into German], which totally bored those who were listening.
Finally, Luther answered them so: “It is nothing significant [for the argument] that Saint Augustine calls the bread a sign of the body of Christ, for based [only] on that we cannot know whether it is his opinion that the body is present or not. For we ourselves hold and claim that it is a sign without discounting that the body is present. The passages, however, where he says that a body must be in one place, are in other contexts, not when he discusses communion. When he writes of communion, he speaks of the body and blood of Christ as we do.” Then Luther presented passages [from Augustine] and said: “Why should we ignore the passages from Augustine which deal directly with communion and turn to those which have nothing to do with communion? Furthermore, if we could be certain that Augustine intended to say what you claim, why should we be fixated solely on Augustine and not more so on Cyprian, Cyril, Ambrose, Jerome, and many others who have outlined our arguments in great detail? And even if all the Church Fathers were of your opinion, why should we forsake the Word of God in favor of following them? Saint Augustine himself commands us to read his books just as he reads the books of others, for he does not believe anything of anyone just because they believe it, no matter how righteous they might be, but only when they prove their point with Holy Scripture. As he does, let us do the dear Fathers the honor of interpreting the writings they have left us as best we are able, so that they remain consistent with Holy Scripture. But where their writings are not compatible with God's Word, it would be much better for us to say, 'they erred,' than to dismiss God's Word on their account.”