Matthew 13:13-14, 35

This is why I speak to them in parables: “Though seeing, they do not see; though hearing, they do not hear or understand. In them is fulfilled the prophecy of Isaiah: “ ‘You will be ever hearing but never understanding; you will be ever seeing but never perceiving.

So was fulfilled what was spoken through the prophet: “I will open my mouth in parables, I will utter things hidden since the creation of the world.”