John Calvin Commentary 1 Corinthians 10:17

"seeing that we, who are many, are one bread, one body: for we are all partake of the one bread." — 1 Corinthians 10:17 (ASV)

For we are one bread. I have already stated above that it was not Paul’s particular design here to exhort us to love. Instead, he mentions this incidentally, so that the Corinthians may understand that we must, even by external profession, maintain the unity that exists between us and Christ, since we all assemble together to receive the symbol of that sacred unity.

In this second part of the statement, he mentions only one part of the Sacrament. It is characteristic of Scripture to describe the entire Supper by synecdoche, using the phrase the breaking of bread. It is necessary to warn my readers in passing concerning this, to prevent any less experienced person from being misled by the foolish quibble brought forward by certain sycophants—as if Paul, by mentioning merely the bread, intended to deprive the people of half of the Sacrament.