One of the less deplorable distractions which can attack a priest while he is offering the Sublime Sacrifice of the Altar is the realisation that he had better check something in Scripture. It happened to me on December 6, S Nic's Day (as we called it at Lancing), while I was reading the Lesson from Hebrews.
I have never studied Hebrews deeply; by which I mean that I never had the opportunity of teaching it as a text for A-level ... that's the best way I know of really getting into a text; examining it daily with ones students for an entire year. But I was aware that sharp critical eyes have wondered why a Letter about the Sacrifice of Christ nowhere mentions the Eucharist. But, last Friday (why never before? The human mind's a strange thing) the text of 13:10 hit me in the eye. "We have a place of Sacrifice [thusiasterion*] from which those who serve [latreuousin] the Tabernacle have no right to eat". Which clearly implies that 'we' do eat of the Thusiasterion which we 'have'.
CUT to the sands of Egypt. Where great mounds of ancient rubbish have yielded scraps of papyrus which have been preserved by the dryness of the desert. Thousands of these, excavated more than a century ago, are in the cellars of the Ashmolean Museum not far from where I write this. And they give us a fresh insight into everyday life in the Greco-Roman world. They include a large number of invitations to the deipnon of a God at his Temple, making it clear that the feast following the sacrifice was, in ancient religion, an integral part of the sacrifice itself. This is why Temples very commonly had, as part of their complex, kitchens and dining rooms. And it is also the reason why S Paul is so concerned (see I Corinthians ... which I have taught) about his converts' dining and eating habits. The religious and the social mingled so closely that it could be very easy to find oneself inadvertently committing idolatry by what one ate, and where.
It is clear to me that Hebrews 13:10 refers in passing to just this connection. The Lord's Table is one with the Altar on High where the Lord eternally pleads his Sacrifice. We eat from this Altar of Sacrifice at the Eucharist. But the non-believing Jews, who still frequent the sacrifices which the Lord abolished in the combined events of the Cleansing of the Temple, the Last Supper, and Calvary, have no right to eat of his Thusiasterion, which is to say, of "our" Eucharist.
(Yes, the NT is unmistakably supersessionist ... if somebody tells you that Nostra Aetate changed all this, ask them to show you which bits of its text they have in mind. But that's a different matter.)
* This term is used by S Ignatius of Antioch with a Eucharistic reference.