This is a parable, but it is not one of the parables of Jesus. This is a parable about parables among other things...
There was once a great desert.
In the middle of the desert was a deep well. It was so deep that people could no longer reach the water to drink.
They could not even see the water in the well. Sometimes you could feel the damp coolness rising from the well, but there was no way to get the refreshing liquid from its depths.
(Sermon begins at 22:14)