William Burkitt on 1 Corinthians 10:17

The apostles argument lies thus: As Christians, though many, yet by virtue of their society in the same worship, are compacted together as it were into one loaf or lump, that is, into one mystical body, in that they partake of one and the same sacramental bread; so those that communicate with idolaters, in eating things offered unto idols, are compacted together as it were into one body, forasmuch as they communicate in one and the same sacrifice: as many grains of corn moulded together make one loaf, and the juice of many grapes make one cup; so Christians, though many, yet are one visible church, one mystical body, and declare themselves so to be by their fellowship together at the Lord's table.