Mark 4:13

And he saith unto them, Know ye not this parable? and how shall ye know all the parables?

As Cranfield noted, this verse "suggests in some sense that the parable of the soils is the key to all the parables."[14] The fact of our Lord's drawing a number of analogies from it would also suggest the propriety of looking for analogies in all the parables. That such a way of interpreting parables is subject to grave abuses, none will deny; but it is equally obvious that the limitation of parables to "one main point" is ridiculous.