To Wolferinus, the pastor who's theory of the Presence appears to have been "cessationist," Luther wrote on July 20, 1543 [my text is from B. Teigen's article, "The Case of the Lost Luther Reference" in CTQ 43.4]:
Indeed, Dr. Philip wrote rightly that there is no sacrament outside of the sacramental action: but you are defining the sacramental action much too hastily and abruptly. If you do it in this way, you will appear to have absolutely no sacrament. For if such a quick breaking off of the action really exists, it will follow that after the speaking of the Words [of Institution], which is the most powerful and principle action in the sacrament, no one would receive the body and blood of Christ, because the action would have ceased. Certainly Dr. Philip does not want that. But such a definition of the action would bring about infinite scruples of conscience and endless questions, such as are disputed among the papists, as, for example, whether the body and blood of Christ, are present at the first, middle, or last syllable. Therefore, one must look not only upon this movement of instant or present action but also on the time. Not in terms of mathematical but of physical breadth, that is, one must give this action a certain period of time, in a period of appropriate breadth of tim, as they say, "in breadth."
Therefore, we shall define the time or [sic in CTQ. Typo for "of"?] the sacramental action in this way: that it starts with the oratio Dominica [CTQ: Our Father. Corrected to the Latin in a personal note from Dr. BTG Mayes]and lasts until all have communicated, have emptied the chalice, have consumed the Hosts, until the people have been dismissed and [the priest] has left the altar. In this way we shall be safe and free from the scruples and scandals of such endless questions. Dr. Philip defines the sacramental action in relation to what is outside it, that is, against reservation of and processions with the sacrament. He does not split it up within [the action] itself, nor does he define it in a way that it contradicts itself. Therefore, see to it that if anything is left over of the sacrament, either some communicants or the priest himself and his assistant receive it, so that it is not only a curate or someone else who drinks what is left over in the chalice, but that he gives it to the others who were also participants in the body [of Christ], so that you do not appear to divide the sacrament by a bad example or to treat the sacramental action irreverently. This is my opinion and I know that it is also Philip's opinion too."
It seems to me that Luther rather forcefully advocates no reservation at all - even for the purposes of distribution. That's the "deal" I mentioned earlier. I characterized it as a "deal" between Melanchthon and Luther because as Timothy Wengert makes clear in this salient article from Lutheran Quarterly, Melanchthon's take on the issue was much more stridently cessationist, or perhaps even receptionist. I highly recommend reading this article - I found it to be necessary to really understanding the points being made.
After reading what Melanchthon had written via Wengert's article, this second letter of Luther quoted above suddenly takes on new meaning. It seems clear to me that Luther is:
* jealously guarding against receptionism - especially with his comments on the Words being the chief action (not eating, as per Missourian Receptionism).
* seeking to remain in unity with Melanchthon by charitably recasting Melanchthon's words (if not outright putting words in his mouth!).
* advocating a practice (complete consummation at the altar) that will make the lasting area of disagreement with Melanchthon moot.
And yes, I think the status of consecrated elements reserved for distribution to the sick remains an area of disagreement between them. Luther's comments in the letter above strongly hint that he would not consider the sacramental action (and therefore the Real Presence) ended until all was distributed - thus leaving open the durationist understanding of elements reserved for distribution to the sick. Melanchthon's comments were at pains to explain how what was once consecrated might not be the Body and Blood of Christ after the "action" was at an end:
"It is sheer raving to imagine that when the celebrant speaks the words the Body
of Christ migrates into the bread in such a way that it is forced to remain there,
as wine poured into a flagon always remains there unless it is again poured out." (Melanchthon, quoted in Wengert).
Here's the historical question to which I do not have the answer: in post-1543 Lutheran lands, was the sacrament reserved for distribution? If so, how were such consecrated elements treated between the end of Mass and the distribution to the sick or shut-in? What, if any, justification did those who reserved for distribution give for jettisoning Luther's strongly worded advice for the pastors in Eisleben?
For my part, I think Luther is right: the sacramental action is, well, the whole sacrament. Indeed, I find this letter a typically refreshing bit of Luther's refusal to play theology. You don't have to read much between the lines to see that he is expressing his usual contempt for theological concepts forced on the text and the church. "Sacramental action"? Where's that in the Bible?
But for the sake of peace, he doesn't quite say that - instead, he uses the term but utterly guts it of Melanchthon's content. The action, and therefore the Presence, is from the Words of the Lord until all has been consumed. Makes sense to me. And if some were to be reserved for the sick? Luther leaves it unanswered - mostly. For his comments about the action lasting until all has been consummed seem to me to be a gentle rebuke to what Melanchthon had written.