Holy Eucharist Teachings by the Fathers of the Church
"Water and blood are a symbol of baptism and the most holy sacrament [of the Eucharist]. Now the Church is founded on the spiritual renewal by the bath of rebirth and on the most holy sacrament [of the Eucharist], both of which have their origin in the side of Christ. Therefore Christ built the Church from the side of Christ, just as he made Eve from the side of Adam. Therefore St. Paul says, 'We are of his flesh and of his bones.'"
Holy Eucharist teachings by the Fathers of the Church - St John Chrysostom (344-407)