1 Corinthians 10:18

Behold Israel after the flesh: have not they that eat the sacrifices communion with the altar? [In Paul's eyes the church was the true Israel, and the Jews were Israel after the flesh. Part of the Jewish sacrifice was eaten by the worshiper as an act of worship (Deuteronomy 12:18), and part was consumed upon the altar as a sacrifice to God; that is, as God's part. Thus the worshiper had communion with the altar, or, more accurately speaking, with God, who owned the altar; a portion of the meat of sacrifice entering his body and becoming part of him, and a portion of it typically entering and becoming part of the Lord. Having thus given two instances showing that sacrificial feasts establish a relationship between the worshiper and the object worshipped, Paul proceeds to make his application of them to idol feasts, and begins by anticipating an objection which the quick-witted Corinthians, seeing the drift of his argument, would begin at once to urge.]