26 He said, “This is how it is with the kingdom of God; it is as if a man were to scatter seed on the land 27 and would sleep and rise night and day and the seed would sprout and grow, he knows not how. 28 Of its own accord the land yields fruit, first the blade, then the ear, then the full grain in the ear. 29 And when the grain is ripe, he wields the sickle at once, for the harvest has come.” 30 He said, “To what shall we compare the kingdom of God, or what parable can we use for it? 31 It is like a mustard seed that, when it is sown in the ground, is the smallest of all the seeds on the earth. 32 But once it is sown, it springs up and becomes the largest of plants and puts forth large branches, so that the birds of the sky can dwell in its shade.” 33 With many such parables he spoke the word to them as they were able to understand it. 34 Without parables he did not speak to them, but to his own disciples he explained everything in private. (Mark 4)
Context. Apart from the Olivet Discourse in Mark 13:3–37, the sacred author’s grouping of parabolic material in Chapter 4 constitutes the largest unit in his Gospel devoted entirely to the teaching of Jesus. Included are three parables of growth: the sower (Ch. 4:3–8), the growth of the seed (Ch. 4:26–29) and the mustard seed (Ch. 4:30–32). Each of the three reflects upon sowing, growth and harvest-elements which illumine the character of the Kingdom of God signaled by Jesus’ presence among them. Yet there is a climate of unbelief that swirls around Jesus: many simply do not appreciate Jesus, the Jewish leadership seems bent upon destroying him (3:6), and he has been accused of forming an alliance with Beelzebul (3:22). Still, the parables not only reflect the situation all about Jesus, more importantly they point to the inevitable and ultimate triumph of the Kingdom of God.
There is certainly a great deal that can be said about Jesus’ use of parables, but as William Lane  points out, especially in the agricultural parables, Jesus is pointing out that the natural order and the life of people is intrinsically like the redemptive order of God. That is not to say merely analogical, but a real correlation because both arise from the purpose of God – both reflect God’s intention and desire
Chapter 4 of Mark contains some very memorable parables:
- Parable of the Sower (vv.1-9)
- Purpose of the Parables (vv.10-20)
- Parable of the Lamp (vv.21-25)
- Parable of the Seed that Grows Itself (vv.26-29)
- Parable of the Mustard See (vv.30-34)
One notable feature of this Markan chapter occurs in early in the chapter when Jesus begins the parable with “Hear this! A sower went out to sow…” (v.3) and then closes the teaching with “Whoever has ears to hear ought to hear.” (v.9) While ending a parable with a plea to discern is typical of the presentation of many parable, the doublet that bookends the first parable of Mark 4 is highly unusual when compared to the traditional Jewish presentation of the masahal/parable. Most scholars take this doublet as an expression that in the hands of Jesus, parables were intended to provoke thought, and were not the transparent illustrations they are sometimes supposed to have been. While this can also be said of the contemporary Jewish use of parables, there is perhaps a dual purpose. First, not only to provide a depth that separates the Spirit-led discerns from the merely curious, but, secondly, to provide an intended degree of obfuscation to investigating Jewish authorities.
After the opening parable of the seed and its explanation (vv.1-20), Mark records five other parables that are meant to enable his audience to take Jesus’ word to heart more personally and more profoundly. By the Parable of the Lamp, Mark suggests that his readers will have to ponder the meaning of Jesus’ life and message much more thoroughly for themselves before they can share it fully with others (vv. 22–23). The parable-like saying about getting back “in the measure you give” (v. 24) is much like the preceding parable about the lamp. Mark’s readers must continuously grow in their understanding of Jesus for themselves, or they will lose what they think they possess. The Parable of the Seed that Grows Itself (or perhaps, the sleeping farmer) (vv. 26–29) sets aside any illusion that the growth of God’s kingdom is somehow indelibly tied to the efforts of any one people. The last parable of chapter 4 is also about a seed, the smallest of all seeds, the mustard seed (vv. 30–32). Even though the early Christian community was small in number, this parable assures Mark’s readers that all their efforts will be fruitful in the growing kingdom of God — if they will just understand (see vv. 33–34)