The familiar ‘parable of the sower’ is all about context:
Jesus said, ‘Now the sower went out, took a handful (of seeds), and scattered them. Some fell on the road; the birds came and gathered them up. Others fell on the rock, did not take root in the soil, and did not produce ears. And others fell on thorns; they choked the seed(s) and worms ate them. And others fell on the good soil and produced good fruit: it bore sixty per measure and a hundred and twenty per measure.’
— Thomas 9 (Lambdin)
If the seed is a sign, the soil is the context in which its meaning appears (or fails to appear). The flower and the fruit are the life transformed or newly guided by that meaning. Thus the internal context – the guidance system of the sign’s interpreter – is essential to whatever guidance is communicated.
In the synoptic gospels, parables like that of the sower may be intended not so much to reveal spiritual truth as to conceal it from the unworthy.
And the disciples came, and said unto him, Why speakest thou unto them in parables? He answered and said unto them, Because it is given unto you to know the mysteries of the kingdom of heaven, but to them it is not given. For whosoever hath, to him shall be given, and he shall have more abundance: but whosoever hath not, from him shall be taken away even that he hath. Therefore speak I to them in parables: because they seeing see not; and hearing they hear not, neither do they understand. And in them is fulfilled the prophecy of Esaias, which saith, By hearing ye shall hear, and shall not understand; and seeing ye shall see, and shall not perceive: For this people’s heart is waxed gross, and their ears are dull of hearing, and their eyes they have closed; lest at any time they should see with their eyes and hear with their ears, and should understand with their heart, and should be converted, and I should heal them. But blessed are your eyes, for they see: and your ears, for they hear. For verily I say unto you, That many prophets and righteous men have desired to see those things which ye see, and have not seen them; and to hear those things which ye hear, and have not heard them.
— Matthew 13.10-17 (KJV)
As Anthony Freeman (1999, 33) points out, this episode in Matthew ‘comes as something of a shock’ to those who assume that Jesus wanted to be understood by everyone. Here he seems to be punishing the gross of heart by casting pearls before them to increase their swinishness, or to widen the gap between those who have understanding and those who have not – ‘as a shepherd separates the sheep from the goats’ (Matthew 25:32-3). The context here is a strongly dualistic sense of justice.