@vjtorley I want to clarify this some more:
This is prime example of how I just see large disconnect.
It is correct that the communion ritual is surprising in an orthodox Jewish context, as it counters so much of our expectations of what they would be willing to do.
Yet historically it appears to be undisputed that the communion ritual arises in the early church in 1st century Palestine. Moreover, no comparable ritual (as I understand) arises in any of the comparable Messiah movements. These are just he brute facts (though I stand to be corrected on the comparators).
The question then is why and how this disparate Jewish community comes to this crazy and new ritual. Why? And how? It is clearly a departure from their context, but also framed within it as one of the Passover glasses. So there is nothing very strong continuity to the Passover lamb, and very high discontinuity at the same time.
This ephiphenic quality to the ritual is truly strange, and perhaps unprecedented. It is best explained as a prophetic epiphany. As Jesus does it, it makes no sense from the disciples context. Only after the crucification and Ressurection does it become clear that Jesus was the true meaning of the tradition he seemed to violating at Passover.
The fact that other Messiah movements did not does the same thing serves to highlight the question. What was it about Jesus that formed the Church so different that they adopted so heterodox customs in this way? The communion ritual is not evidence against the Ressurection for this reason. It is one of the details that highten the urgency of the question that Alter appears to blow right by, and certainly you review did.
Yes it is unlikey. We also have no doubt it happened in the early church. If not how the Church itself explained it, then how? Without a robust explanation for all the crazy things that happened in the early church ( and did not happen), Alters analysis is just blowing by the most salient questions of that moment.