The Bread of Life Discourse is a portion of the teaching of Jesus which appears in the Gospel of John 6:22-59 and was delivered in the synagogue at Capernaum:
26 Jesus answered them, Truly, truly, I say to you, In Hebrew, Greek and Latin Amen, Amen. We normally end our prayers with Amen but Jesus begins His statement in this manner. Amen means truly, truly. The doubled Amen is a solemn affirmation, an oath. The faithful and true witness is Christ, the Amen (Rev 3:14). Since two witnesses are required to sentence someone to death (Deut 17:6), Jesus is bearing the part of both witnesses and alerting them that what he is going to say has life and death consequences.
51 I am the living bread which came down from heaven; The third time (verses 35 & 48) that He identifies Himself as the Bread of Life. In Hebrew numerology the number three represents completeness. Jesus does not attempt to soften or alter His teaching. It is the literal meaning, not a figurative or metaphorical one, that He is trying to drive home. if anyone eats of this bread, he will live forever; and the bread which I shall give for the life of the world is my flesh.
The Eucharistic theme has been reached; the mystery has been revealed (see also Heb 10:5-10).
52 The Jews then disputed among themselves, saying, how can this man give us his flesh to eat?
Many of the hearers have understood perfectly well what Jesus is saying and that He means exactly what He says, but they can’t believe that what He says could be true. How can He give them His flesh to eat?
If they had understood Him in a metaphorical, figurative or symbolic sense, there would have been no reason for them to quarrel. Just as Nicodemus thought of being born again in the purely physical sense (Jn 3:4), and the woman at the well thought only of natural water (Jn 4:11), so now the Jews understand the reference to His flesh literally.
53 So Jesus said to them, truly, truly, I say to you. This is the fourth time He has reminded them that this is a life and death situation. unless you eat the flesh of the Son of Man (recall that Son of Man is a term which Jesus applies to Himself, the New Adam (Dan 7:13), 8 the one who will affect the resurrection)
(Ez 37). Jesus' words do not encourage any figurative understanding of His pronouncement; they only underscore the literal meaning. and drink his blood, If the idea of eating someone’s flesh is repugnant, what about drinking their blood? To the Jewish audience this would be even more repulsive. Blood was a forbidden food under the Law (Lev 7:27; 17:10-14), the penalty for which was to be expelled from the tribe; they would be excommunicated.
Flesh and blood are a common Old Testament expression for life. When the two are separated, death results. By taking both, they must be partaking of a living being. you have no life in you; are dead, no spirit.
54 he who eats my flesh The Greek verb used here is much stronger than just eating, it literally means gnaw, gnaw. This shows that it is a real meal that He is talking about. There is now absolutely no room for saying that He is speaking symbolically. Not only has He reiterated the statement, He has strengthened His response.