"'The great Athanasius in his sermon to the newly baptized says this:' You shall see the Levites bringing loaves and a cup of wine, and placing them on the table. So long as the prayers of supplication and entreaties have not been made, there is only bread and wine. But after the great and wonderful prayers have been completed, then the bread is become the Body, and the wine the Blood, of our Lord Jesus Christ. 'And again:' Let us approach the celebration of the mysteries. This bread and this wine, so long as the prayers and supplications have not taken place, remain simply what they are. But after the great prayers and holy supplications have been sent forth, the Word comes down into the bread and wine - and thus His Body is confected."
-"Sermon to the Newly Baptized" ante 373 A.D.