The Ancient Pateric:
1) "Abba Daniel also told, saying: our father Abba Arseny said about a certain wanderer who was great in life, but simple in faith, but was mistaken in his ignorance and said that bread, which we accept, is not essentially the Body of Christ, but that it is only an image. And the two elders heard that he was saying such words, and knowing that he was great in life, they judged that he was speaking in kindness and simplicity, and came to him and said to him: Abba! We have heard the speech of an infidel who says that the bread we accept is not essentially the Body of Christ, but only his image. But the elder said: I am saying this. But they admonished him, saying: Do not hold on like this, Abba, but as the universal Church betrayed. For we believe that the very bread is the Body of Christ and the very cup is the Blood of Christ truly, and not figuratively. But just as God first took a finger from the earth and formed man in His own image, and no one can say that he was not the image of God, although it is incomprehensible, so about the bread, of which He said: this is My Body, we believe that it is truly the Body of Christ. The elder said: if I am not convinced by the deed, I will not be sure. But they said to him: Let us pray to God this week for this Sacrament and believe that God will reveal it to us. The elder joyfully accepted this word and prayed to God, saying: You, Lord, know that I do not believe out of malice, but that I may not err from the truth; reveal to me, Lord Jesus Christ, what is true. But even the elders, retiring to their cells, prayed to God, saying: Lord Jesus Christ, reveal to the elder what this sacrament is, so that he may believe and not ruin his work. And God heard them both, and when the week was over, they came to church on Sunday and sat down separately on a mat, and in the middle was the elder. But their wise eyes were opened, and when the bread was laid at the holy table, only the three of them saw, as it were, a baby. And when the presbyter stretched out his hand to crush the bread, behold, the angel of the Lord came down from heaven with a knife, and slaughtered the child, and poured out his blood into the cup. But when the presbyter broke the bread into small pieces, and the angel cut off small pieces from the baby. When they came to receive holy communion, only the bloody flesh was given to the elder. And when he saw this, he was horrified and cried out, saying, I believe, Lord, that the bread offered on the throne is your body and the cup is your Blood. And immediately the flesh in his hand became bread, as happens in the Sacrament, and he accepted, thanking God. And the elders said: God knows human nature, that it cannot eat raw flesh, and therefore it transforms its body into bread and its blood into wine for those who accept it with faith. And they thanked God for the elder that God had not allowed his labors to perish, and all three went joyfully to their cells."
2) "He also said about another certain brother: when there was prayer on Sunday and he got up as usual to go to church, the devil laughed at him, saying: where are you going? To the church? And why? Or to get bread and wine? And they will tell you that this is the Body and Blood of the Lord - do not expose yourself to ridicule. The brother believed the thought and did not go to church. The brethren were waiting for him, for it was the custom not to begin prayer until everyone had gathered. But he hesitated; and they came to him, saying, "Perhaps my brother is ill," and finding him in his cell, they asked him the reason why he did not go to church. But he, though ashamed to tell them the reason, nevertheless says to them: forgive me, brethren: I got up as usual and prepared to go to church, and told me the thought that it is not the Body and Blood of Christ that you are going to receive, but simple bread and wine. So, if you want me to go with you, correct my thoughts about the Holy Spirit. An offering. But they said to him: Get up, come with us, and we will ask God to reveal to you the divine power present in the holy Church. And getting up, he went with them to church. And having prayed a lot for the brother to God, so that the power of the divine Sacraments would be revealed to him, they began to perform the service, and the brother was placed among the church. And until he was released, he did not stop watering and dousing his face with tears. After the service, having begun, they asked him: what has God revealed to you, tell us so that we may benefit. He began to tell them with tears: when the canon of psalmody was read and the apostolic teaching was read, and the deacon went out to read the Gospel, I saw that the roof of the church opened and the sky was visible, and every word of the Gospel was like fire and ascended to heaven. But when the holy Gospel was finished and the clergy left the deaconess, having the holy Sacraments, I saw that the heavens opened again and fire descended, and with fire a multitude of holy angels and among them two other wonderful faces, the beauty of which cannot be told. And their radiance was like lightning, and among the two faces was a little boy. And the holy angels stood around the holy table, and two faces above it, and a boy in the middle of them. And when the holy prayers were over and the clerics approached to break up the loaves of communion, I saw that two persons began to hold the baby by the hands and feet, and took a knife, and stabbed him, and poured his blood into a chalice, and dissecting his body, put it on top of the loaves, and the loaves became a body. When the brethren came to receive, a body was given to them, and when they cried out, saying, Amen, it became bread in their hands. When I also came to receive, a body was given to me and I could not taste it, and I heard a voice saying to me: What are you not taking? Isn't that what you were looking for? And I said, Be merciful to me, Lord! I can't taste the body. And he said to me: if a man could eat the body, the body would be found, as you have seen, but since no one can eat meat, therefore the Lord has established loaves for communion. So, will you accept with faith what you hold in your hand? And I said, I believe, Lord. And when I said this, the body that I held in my hand became bread, and, thanking God, I accepted the holy prosphora. When the service ended and the clerics went to their place, I saw again a baby among two animals, and when the clerics consumed the holy gifts, I saw that the roof of the church was opened again and divine Forces ascended to heaven. When the brethren heard this, they remembered the apostle saying: Christ was devoured for our Passover. And they went to their cells in emotion, praising and praising God, who works great miracles."