Why this language means that is never explained, but it is axiomatic.
SD
Therefore many of his disciples, when they heard this, said, "This is a hard saying! Who can listen to it?" But Jesus knowing in himself that his disciples murmured at this, said to them, "Does this cause you to stumble? Then what if you would see the Son of Man ascending to where he was before?They were saying "He can't seriously mean it" and Jesus answers "If you can't believe what I tell you in plain language, how will you ever understand when I am gone"
He is proven right once again.
"My words are Spirit and Life" - Can only mean "what I say to you is True and you had better accept it"
How does saying that something is "spiritual" mean that it is not to be taken seriously?