Yes Jesus did explain it first, you posted it. He said the bread that he will give is his FLESH ..... Every reference to the word "flesh" thereafter refers back to this statement.
I think you need to go back into history to understand it better. This might help.
You can say "then he repeats", sure, but he already explained it first.
You know how much Jesus used symbolism in the Bible and how much of it was cultural. You have read the Bible before enough to see the patterns here.
Your first mistake is including an extra biblical source to try and explain what Jesus "really" meant. Your second mistake is assuming that Jesus doesn't mean what he's saying and you need to explain it to me. It you feel compelled to tell me what Jesus "really" meant then I'm listening to you not him. Won't happen.