If youread all of John 6, you see the Jews grumbling over Jesus' statements that they must eat his flesh, finding it a hard statement to understand. The translation of Jesus' words is very literal,i.e., to chew or gnaw. I believe that Jesus repeats himself 3 times on this point to the Jews growing consternation. He does not say to them that they are takinghim to literally, like when he clarifies his statements about being "born again."
Ultimately these disciples leaave him an d no longer follow him . If he was speaking figuratively, why would they leave? Because he wasn't.
25When they found him on the other side of the sea, they said to him, "Rabbi, when did you come here?" 26Jesus answered them, "Truly, truly, I say to you, you are seeking me, not because you saw signs, but because you ate your fill of the loaves. 27 Do not labor for the food that perishes, but for the food that endures to eternal life, which the Son of Man will give to you. For on him God the Father has set his seal."
"61But Jesus, knowing in himself that his disciples were grumbling about this, said to them, "Do you take offense at this? 62Then what if you were to see the Son of Man ascending to where he was before? 63 It is the Spirit who gives life; the flesh is no help at all. The words that I have spoken to you are spirit and life. 64But there are some of you who do not believe." (For Jesus knew from the beginning who those were who did not believe, and who it was who would betray him.) 65And he said, "This is why I told you that no one can come to me unless it is granted him by the Father."
66 After this many of his disciples turned back and no longer walked with him. 67So Jesus said to the Twelve, "Do you want to go away as well?" 68Simon Peter answered him, "Lord, to whom shall we go? You have the words of eternal life, 69and we have believed, and have come to know, that you are the Holy One of God."
This was a test for those following Jesus. It came right after the feeding of the 5000. Those who were looking for bread or an earthly king left. Those who believed remained.
Jesus was plenty clear.
"28Then they said to him, "What must we do, to be doing the works of God?" 29Jesus answered them, "This is the work of God, that you believe in him whom he has sent." 30So they said to him, "Then what sign do you do, that we may see and believe you? What work do you perform? 31 Our fathers ate the manna in the wilderness..."
Jesus was talking about belief. THEY were looking for miracles. Jesus didn't WANT to keep disciples who wanted a good show...
Nicodemus, on the other hand, was asking sincerely. "39 Nicodemus also, who earlier had come to Jesus by night, came bringing a mixture of myrrh and aloes, about seventy-five pounds in weight. 40So they took the body of Jesus and bound it in linen cloths with the spices..." - John 19