Here is the text, based on Matthew’s account, but including significant variants from Mark and Luke.

Mt 13:1 On that day after Jesus went out of the house, he sat by the lake. 13:2 And such a large crowd gathered around him [Lk: and people were coming to Jesus from one town after another] that he got into a boat to sit while the whole crowd stood on the shore. 13:3 He told them many things in parables [Lk: he spoke to them in a parable], saying: “Listen! A sower went out to sow. 13:4 And as he sowed, some seeds fell along the path [Lk: and was trampled on], and the [Lk: wild] birds came and devoured them. 13:5 Other seeds fell on rocky ground [Lk: rock] where they did not have much soil. They sprang up quickly because the soil was not deep. 13:6 But when the sun came up, they were scorched, and because they did not have sufficient root, they withered [Lk: and when it came up, it withered because it had no moisture]. 13:7 Other seeds fell among the thorns, and they grew up and choked them [Mk: and it did not produce grain]. 13:8 But other seeds fell on good soil [Lk: and grew]and produced grain (Mk: sprouting and growing], some a hundred times as much, some sixty, and some thirty [Lk: it produced a hundred times as much grain]. 13:9 The one who has ears had better listen!”

Mk 4:13 adds: He said to them, “Don’t you understand this parable? Then how will you understand any parable?

13:18 “So listen to the parable of the sower [Lk: Now the parable means this: the seed is the word of God][Mk: The sower sows the word]: 13:19 When anyone hears the word about the kingdom and does not understand it, the evil one [Lk: the devil][Mk: Satan] comes and snatches what was sown in his heart [Lk: so that they may not believe and be saved]; this is the seed sown along the path. 13:20 The seed sown on rocky ground is the person who hears the word and immediately receives it with joy. 13:21 But he has no root in himself and does not endure [Lk: They believe for a while]; when trouble or persecution comes because of the word, [Lk: in a time of testing] immediately he falls away. 13:22 The seed sown among thorns is the person who hears the word, but worldly cares and the seductiveness of wealth [Lk: worries and riches and pleasures of life][Mk: worldly cares, the seductiveness of wealth, and the desire for other things] choke the word, so it produces nothing [Lk: their fruit does not mature]. 13:23 But as for the seed sown on good soil, this is the person who hears the word [Lk: clings to it] and understands [Lk: after hearing the word, cling to it with an honest and good heart].  He bears fruit [Lk: with steadfast endurance], yielding a hundred, sixty, or thirty times what was sown.  [Mk: one thirty times as much, one sixty, and one a hundred]”

It should be noted that many scholars doubt the authenticity of Mt 13:18-23 and parallels.  Blomberg (The Historical Reliability of the Gospels) summarises the reasons for such doubt:

(a) as a skilled teller of parables, Jesus would not need to explain them, just as a skilled comedian does not need to explain his jokes; he would have been especially unlikely to have given a detailed allegorical interpretation, such as we have here;

(b) this interpretation, focusing as it does on the different kinds of soil, misses the main point of the parable, which stresses the scale of the harvest from the seed that fell in good soil;

(c) the language of the interpretation is unlike the language of Jesus, and more like the language of a Hellenistic church.

In response to (a), which Blomberg describes as the most forceful of these objections, it should be stated that rabbinic parables usually ended with explanations, and often with quite detailed allegorisations.  Whereas subsequent interpretations of Jesus’ parables have sometimes engaged in allegorisations that would not have been comprehensible to their first hearers, there is nothing in in the interpretation attributed to Jesus of that nature.  In fact, Jesus’ interpretation would have been readily understood and appreciated by the people of his own day.

Witherington is one of those who thinks that

‘in its present form, this explication and application seems to reflect the language of the early church, using words not elsewhere found in the teaching of Jesus, but rather in the epistles (e.g., λογος in the sense of gospel, cf. Gal. 6:6; 1 Thess. 1:6; προσκαιρος, 2 Cor. 4:18, in the sense of short-lived; μεριμναι, meaning cares, cf. 1 Pet. 5:7; η απατη, Col. 2:8, seduction).’

Edwards says that Jesus’ interpretation of the parable forces us to consider what a parable is and does:

‘Parables are a plastic rather than a static medium. They are not bricks, dried hard and fast in the sun, but wet clay that invites new impressions. Whether the new impressions are made by the hands of the potter or by later apprentices is very difficult to say, and for Mark’s purposes unimportant.’

Although initiated into the mystery of God’s Kingdom, they were still slow to understand. If they cannot understand this parable, all the others will remain obscure to them also. The Parable of the Sower is a key to all parables, because it describes the different degrees of receptiveness of the human heart to the word of God, which different degrees it is the general design of the parables to expose.

All the gospel accounts agree that this was the first parable spoken by Jesus. Indeed, here begins a phase when the parabolic method became Jesus’ primary means of teaching, Mk 4:33-34. Accordingly, the disciples expressed their surprise and puzzlement over this new form of teaching, Mk 4:10.

Snodgrass outlines the importance of this parable:

‘It is the first substantive parable in all three [Synoptic Gospels] and, other than Matthew’s parables of the Wheat and the Weeds and of the Net, is the only parable given a detailed interpretation.1 It and the Wheat and the Weeds are the only two parables given a title (Matt 13:18 and 36). The Sower is unique in that it is given pride of place in each Gospel at the beginning of crucial instruction on parables and the kingdom (Matt 13:1-52/Mark 4:1-34/Luke 8:1-18). It is the parable about parables.’

Edwards discusses Mk 4:13, and the question of why understanding this parable is key to understanding all the parables of Jesus.  Noting that this verse is absent in Matthew and Luke, he suggests that the parable of the sower picks up two themes that are central to Mark’s message: Christology (in vv3-9, where the seed is the word/gospel) and discipleship (in vv14-20, where the seed becomes the hearers).

So far as general interpretative questions are concerned, Snodgrass suggests that the following require particular attention:

1. What is the significance of the structure of Mark 4, Matthew 13, and Luke 8? […]
2. How are the difficult words of Mk 4:10-12 to be understood? […]
   1. Is this text about “double predestination”?
   2. Who are those on the “outside” in Mark and how does one get inside?
   3. What is the significance of the use of Isa 6:9-10?
   4. What is the meaning of hina (usually “in order that”) and mēpote (either “lest,” “whether,” or “perhaps”) in Mark 4:12?
   5. What is the intent with such words as “parables” in the plural (Mark 4:10), mystērion (“mystery,” v. 11), and ta panta (“all things,” v. 11)?
   6. The statement “To those outside all things come in parables” is especially unsettling because in all three Synoptics Jesus has been teaching the crowds without parables and has been understood as one teaching with authority, most obviously in Matthew and Luke with their Sermons on the Mount/Plain, but also in Mark 1:15, 21-22, 38-39.

3. Does the interpretation belong originally with the parable or is it a result of early church allegorizing? […]
4. Would anyone sow seed this way?
5. Is the analogy about God sowing people in Israel or God sowing his word?
6. What is the meaning and significance of this parable and its context? Is the focus on the sower, the seed, the soil, or the harvest? Specifically, what does it tell us about the kingdom?
7. How has the redactional shaping of each Evangelist impacted the nuance of the parable?

The elements: the seed (representing the word of God, Lk 8:11); the Sower (representing Christ, Christ, cf v37, and by extension his ministers, 1 Cor 3:9); the soil (representing 4 types of human heart with 4 different responses to the word of God). The main thought: the growth of the seed depends on the quality of the soil. That is, the results of the hearing of the gospel depend upon the condition of the human heart. Not all hearers of the word profit by it.

In Mk 4:14, the seed is the word; whereas in the next verse it becomes the hearers of the word. Moreover, the explanation of the parable contains a number of words that do not occur elsewhere in Mark (although they do occur in Paul).  Again, the various obstacles to hearing (vv17, 19) are thought to reflect a later period.  To some, these considerations suggest that this section stems from the early church and not from the lips of our Lord.  Edwards, amongst others, thinks that the explanation of the parable can quite readily be understood as coming from the lips of Jesus.  In any case, says Edwards, parables are fluid, rather than fixed in meaning.  Even if later minds did adapt and re-apply certain aspects, this does not undermine either the original story or its later re-interpretation.

Blomberg remarks:

‘Whether the people are meant to correspond to the seed or to the soils is more a problem for us than for Aramaic speakers. Soil sown with seed, as a whole, is in view in each case.’

There was never anything wrong with the seed! The outcome depended on the reception given to the seed. So it is with the word of God. There is no deficiency in it; its variable effectiveness depends entirely on the receptiveness of the heart.

The fact that the seed is sown everywhere – in unpromising places as well as promising places – is richly suggestive for Christian evangelism.  The word is to be sown everywhere.  As Garland says, if the sowing had been left to the Pharisees, they would have severely restricted the terrain where the seed was to be sown – lepers, prostitutes and tax collectors would be excluded.

We should not despair over apparent failures.  Jesus himself met with rejection and opposition, but this did not stop him from sowing the seed of God’s word.

Ryrie characterises the four responses as: no response; emotional response, wordly response, and truitful response.

‘Marcus helpfully suggests that we should notice that each of the failures occurs at a different stage in the maturation process—the first seed scattered doesn’t even germinate, the second withers away as soon as it sprouts up, the third grows but seems to produce no fruit.’ (Witherington)

Edwards (on Mark) comments:

‘So intent is the farmer on a harvest that he sows in every corner of the field “in hopes that good soil might somewhere be found,” said Justin Martyr in his retelling of the parable over a century later (Dial. Trypho 125.1–2). Even so, rocks, thorns, and adverse elements render three-quarters of the labor lost.’

It should be noted then, that the effectiveness of the gospel does not depend (only) upon the efforts of the preacher, but upon the disposition of the hearers. The pulpit is criticised often; the pew seldom. It is good for ministerial students to be taught how to preach, but also good that our congregations be taught how to hear. The preacher is called to sow the seed of the word indiscriminately, and does not hold sole responsibility for its effects. There is a common call of the gospel to the many, and an effectual call to the few, Mt 22:14. We should be be surprised by a relative lack of success: three types of soil were bad, and only one good, cf Isa 53:1.

Blomberg cites Kistemaker on the overall message of the parable:

‘The Word of God is proclaimed and causes a division among those who hear; God’s people receive the Word, understand it, and obediently fulfill it; others fail to listen because of a hardened heart, a basic superficiality, or a vested interest in riches and possessions.’

What this parable teaches about the kingdom

According to Snodgrass,  the parable addresses both nation and individuals, teaching that:

1. ‘The kingdom is a kingdom of the word; it involves a proclamation about God and God’s purposes and actions.’
2. ‘The kingdom presents a challenge for people to hear perceptively respond obediently.’
3. ‘The kingdom is presently at work as people respond with believing obedience.’

Blomberg (Preaching the Parables) suggests that each of these four types of hearers are readily apparent among the original hearers of Jesus’ message:

1. Many of Jesus’ opponents – particularly those from the Jewish establishment – never wavered in their hostility towards him.  They were unresponsive pathway hearers.

2. There were large crowds who followed Jesus, admiring his miracles and his teaching.  But, when the going got tough, they fell away.  See, for example, the end of John 6.  They were impulsive stony ground hearers.

3. There was Judas, one of the inner circle of twelve disciples, who followed Jesus almost all the way, but showed his true colours right at the end.  He was a thorny ground hearer, led astray by his love of money and (probably) by false hopes that Jesus would lead a nationalistic uprising.

4.  Finally, there were the remaining eleven disciples, who represent those who, though imperfect in many ways, were mightily empowered in order that the church of Christ might be established and grow.

Klyne Snodgrass warns modern preachers:

‘The parable emphasizes both receptivity and bearing fruit. Two of the three sowings that fail describe people who respond positively to the message. They even hear the message with joy, but their hearing is still superficial. Receiving the kingdom with joy is not enough — a message the modern church desperately needs to hear. Faith that is temporary and unproductive is not true faith. Most pastors would be quite happy if people received the word with joy or made claims about faith, but this parable asserts that people can receive the word with joy and still be guilty of hardness of heart. Any hearing that does not result in productive living in relation to the Father is not valid hearing. As C. Keener observes, “the only conversions that count in the kingdom are those confirmed by a life of discipleship.”’

And preachers should not fail to warn people of the importance of fruit-bearing in their Christian lives:

‘Fear that a concern for productive living leads to legalism only shows how much people have misunderstood Jesus’ message.  Does initially receptive hearing that eventually fails raise the question of eternal security? People are overly vexed with the question of eternal security because of inadequate understandings of faith. This parable does not address the question of eternal security; it raises the question of inadequate and unproductive hearing. Churches should not be complicit in allowing people to think an initial response unaccompanied by productive living is saving faith.’