and this one:

“Very truly I tell you, unless you eat the flesh of the Son of Man and drink his blood, you have no life in you. Whoever eats my flesh and drinks my blood has eternal life, and I will raise them up at the last day. For my flesh is real food and my blood is real drink. Whoever eats my flesh and drinks my blood remains in me, and I in them. Just as the living Father sent me and I live because of the Father, so the one who feeds on me will live because of me."

THAT is a commandment too. The greek word for "eat" here is trogo. Literally, to gnaw, to masticate. There is no symbolism here, just a very direct, command. If it was just symbolic, so many disciples would not have left.