Does anyone have a reference or book for the Orthodox teaching that the Eucharist is changed metaphysically as noted here? Thanks in advance
"Eucharist: from the Greek eukharistiā (thanksgiving). The central act of Christian worship. Also called Holy Communion, the Lord’s Supper, the Blessed Sacrament, the Divine Liturgy, or Mass according to tradition. The rite celebrates the Last Supper of Jesus with his disciples (Mark 14 and parallels) and is one of Christianity’s earliest institutions (see 1 Corinthians 11). The taking of bread and wine in commemoration of Jesus giving his body and blood has been a source of much controversy as to the exact nature of the elements and their meaning. For Orthodoxy and Roman Catholicism, at the point of consecration the bread and wine undergoes a metaphysical transformation (transubstantion) and becomes the body and blood of Jesus Christ. For many Anglicans and Lutherans, the event instead signifies the real or spiritual presence of Jesus with the communicants. Other Protestant groups see it as a memorial event with only symbolic significance. All Christian traditions regard the Eucharist as an important event in the communal life of the Church."
Backhouse, Stephen. Zondervan Essential Companion to Christian History. Grand Rapids, MI: Zondervan, 2019. Print.