19 [54-58] Eats: the verb used in these verses is not the classical Greek verb used of human eating, but that of animal eating: "munch," "gnaw." This may be part of John's emphasis on the reality of the flesh and blood of Jesus (cf John 6:55), but the same verb eventually became the ordinary verb in Greek meaning "eat."
20 [60-71] These verses refer more to themes of John 6:35-50 than to those of John 6:51-58 and seem to be addressed to members of the Johannine community who found it difficult to accept the high christology reflected in the bread of life discourse.
21 [62] This unfinished conditional sentence is obscure. Probably there is a reference to John 6:49-51. Jesus claims to be the bread that comes down from heaven (John 6:50); this claim provokes incredulity (John 6:60); and so Jesus is pictured as asking what his disciples will say when he goes up to heaven.
22 [63] Spirit . . . flesh: probably not a reference to the eucharistic body of Jesus but to the supernatural and the natural, as in John 3:6. Spirit and life: all Jesus said about the bread of life is the revelation of the Spirit.
Therefore I say to the Israelites, "None of you may eat blood, nor may an alien living among you eat blood."
"Think not that I am come to destroy the law, or the prophets:For verily I say unto you, Till heaven and earth pass, one jot or one tittle shall in no wise pass from the law...."
He also told the Apostles to "do this", that is, He commanded them to be priests (Luke 22:19).