John 10:6

Jesus told them this allegory, but they did not understand what he was saying to them;

Matthew 13:13-14

This is why I speak to them in parables, because for all their seeing they do not see and for all their hearing they do not hear or understand.

Matthew 13:51

Have you understood all this?" They said to him, "Yes."

John 6:52

The Jews then wrangled with one another, saying, "How can he give us his flesh to eat?"

John 6:60

Now many of his disciples, on hearing it, said, "This is hard to take in! Who can listen to talk like this?"

John 7:36

What does he mean by saying, 'You will search for me but you will not find me, and where I go, you cannot come'?"

John 8:27

They did not understand he was speaking to them about the Father;

John 8:43

Why do you not understand my speech? Because you are unable to listen to what I am saying.

John 16:25

I have told you this in figures, but the time is coming when I shall speak to you in figures no longer; I shall let you know plainly about the Father.

1 Corinthians 2:14

The unspiritual man rejects these truths of the Spirit of God; to him they are 'sheer folly,' he cannot understand them. And the reason is, that they must be read with the spiritual eye.

1 John 5:20

We know that the Son of God has come, and has given us insight to know Him who is the Real God; and we are in Him who is real, even in his Son Jesus Christ. This is the real God, this is life eternal.

Treasury of Scripture Knowledge

Summary

This parable spake Jesus unto them: but they understood not what things they were which he spake unto them.

General references

Bible References

They understood not

John 6:52
The Jews then wrangled with one another, saying, "How can he give us his flesh to eat?"
John 7:36
What does he mean by saying, 'You will search for me but you will not find me, and where I go, you cannot come'?"
John 8:27
They did not understand he was speaking to them about the Father;
Matthew 13:13
This is why I speak to them in parables, because for all their seeing they do not see and for all their hearing they do not hear or understand.
1 Corinthians 2:14
The unspiritual man rejects these truths of the Spirit of God; to him they are 'sheer folly,' he cannot understand them. And the reason is, that they must be read with the spiritual eye.
1 John 5:20
We know that the Son of God has come, and has given us insight to know Him who is the Real God; and we are in Him who is real, even in his Son Jesus Christ. This is the real God, this is life eternal.

General references

Luke 18:34
However, they did not understand a word of this; indeed the saying was hidden from them, and they did not know what he meant.