John Calvin on 1 Corinthians 11:20

20. This is not to eat the Lord’s supper He now reproves the abuse that had crept in among the Corinthians as to the Lord’s Supper, in respect of their mixing up profane banquets with the sacred and spiritual feast, and that too with contempt of the poor. Paul says, that in this way it is not the Lord’s supper that is partaken of — not that a single abuse altogether set aside the sacred institution of Christ, and reduced it to nothing, but that they polluted the sacrament by observing it in a wrong way. For we are accustomed to say, in common conversation, that a thing is not done at all, if it is not done aright. Now this was no trivial abuse, as we shall afterwards see. If you understand the words is not as meaning, is not allowable, Paraeus and some others take the words ὀυκ ἔστι is not, as used for, ουκ ἔξεστι is not allowable. — Ed the meaning will amount to the same thing — that the Corinthians were not in a state of preparation for partaking of the Lord’s supper, as being in so divided a state. What I stated a little ago, however, is more simple — that he condemns that profane admixture, which had nothing in it akin to the Lord’s Supper.