Which source hypothesis has a simpler explanation of this data?

Any source theory needs to be supported by redaction criticism & account for any parallels or variations in content. Only a hypothesis that is consistent with each gospel's editorial tendencies at other points can be considered plausible.

The fact that the parables presented here by Matthew & Mark share several characteristics (i.e., comparison of the divine kingdom to a farmer anticipating a harvest & other key words) suggests some genetic relationship. Theoretically they may be siblings generated at different moments in the oral Jesus tradition; or one may be the direct literary offspring of the other.  

Still, Matthew chose to present only one & Mark only the other at approximately the same point in their narratives.  So, the primary questions relevant to the synoptic problem are: which of these two harvest cycle parables is likely to have been substituted for the other & why? 

A second set of questions concerns the source of the details of the substituted parable.  Is one parable simply the product of one synoptic author's creative revision of a theme presented by the other's text? Or can the variant be credited to some other source that is no longer extant?

A theory that envisions the synoptic authors using some source for Jesus' sayings outside our canonical gospels (D) clearly has more options available to explain their divergent treatment of these harvest parables than any hypothesis (A, B or C) that regards all differences in Matthew, Mark & Luke as simply the result of the later writer's innovative reworking of one or more earlier synoptic narratives.

A	Did Mark edit Matthew?

The fact that Mark's harvest parable is less than half the length of Matthew's might seem to support Augustine's view that Mark abbreviated Matthew. Yet, the crucial differences in plot make it impossible to interpret the scene portrayed by Mark as simply a less verbose version of that recorded in Matthew. 

If Mark edited Matthew, then he deliberately

• dropped the initial dichotomy between both good seed & weeds & the farmer & his enemy, 
• changed the characterization of the farmer from alert & knowledgeable to inactive & ignorant,
• eliminated the figures of the servants, &
• altered the conclusion in which some are saved & the rest destroyed.

Why Mark would have decided to make these editorial changes here in a parable designed to illustrate the kingdom of God is unclear. For the details of Matthew's parable fit well within Mark's own representation of Jesus' message. 

Elsewhere Mark repeatedly associates the theme of God's kingdom with an eschatological crisis, in which some are saved & others destined to be consumed or destroyed. He introduces Jesus' public career with the proclamation:

Mark 1
15	"The time is fulfilled!
	The kingdom of God is at hand!
	Repent! and believe in the gospel."

Mark follows this announcement with scenes in which Jesus expels unclean spirits. Then, just before this section on parables, Mark presents this response by Jesus to charges by skeptical scribes that he performs exorcisms as an agent of the "prince of demons":

Mark 3
23	And he called them to him,
	and said to them in parables:
	"How can Satan cast out Satan?
24	If a kingdom is divided against itself,
	that kingdom cannot stand...
26	And if Satan has risen up against himself
	and is divided, he cannot stand,
	but is coming to an end."

Then, after presenting Jesus' assurance that some of his disciples will live to see "that the kingdom of God has come with power" [9:1], Mark cites this dire warning:

Mark 9
47	"And if your eye causes you to sin, pluck it out;
	it is better for you to enter the kingdom of God with one eye
	than with two eyes to be thrown into hell,
48	where their worm does not die,
	and the fire is not quenched."

Finally, Mark concludes Jesus' preaching with a promise that in the end the chosen will be saved: 

Mark 13
27	"And then he will send out the angels
	and gather his elect from the four winds
	from the ends of the earth to the ends of heaven."

So,  Mark obviously regarded Jesus as herald of God's kingdom who rid the world of spirits planted by Satan. And he clearly thought that those who were not gathered into God's kingdom were destined to be consumed by fire. Why, then, would he suppress the imagery of Matthew's harvest parable or replace it with an illustration of God's kingdom that does not mention an eschatological separation of God's chosen seed from those planted by the Adversary?  Though Matthew's insistence that the weeds be left undisturbed until the time of harvest does not exactly fit Mark's own urgent eschatology, that still does not explain why the Markan version of a harvest parable fails to mention the weeds & their destruction at all.

Moreover, Mark regularly contrasts Jesus' knowledge of the true nature of God's kingdom with misunderstanding on the part of his disciples [e.g., Mark 4:13].  The only thing Mark represents Jesus as not knowing is the exact time of the final gathering; that, he stresses, is known only to God [Mark 13:32]. The contrast between the master's clairvoyance & his servants' faulty understanding & misguided zeal in the Matthean harvest parable [Matt 13:27f] would, therefore,  provide a perfect illustration of a characteristically Markan motif that Mark himself introduced only a few lines earlier: that is, Jesus' own disciples failure comprehend what their master himself understood. So, if Mark edited Matthew, it is a complete mystery why he deliberately

• eliminated the figures of the perplexed servants &
• replaced Matthew's portrayal of the farmer's wisdom with an explicit declaration of his ignorance [Mark 4:27].   

Thus, the Augustinian theory of synoptic redaction does not adequately account for the details of the gospel narratives at this point.

B	Did Mark conflate Matthew & Luke?

Griesbach's view of the relationship of the synoptic gospels hardly offers a better basis than Augustine's source theory for explaining the differences between the harvest parables in Matthew & Mark. Since Luke does not report any harvest parable, Mark's divergence from Matthew at this point cannot be attributed to Lukan influence. If Mark knew that Luke omitted Matthew's harvest parable he had three editorial options:

• he could follow Luke and omit Matthew 's parable; or
• he could ignore Luke and copy Matthew's parable; or
• he could edit Matthew's parable to illustrate his own view of God's kingdom better.

But it is obvious that he has done none of these. Rather, he presented a harvest parable that not only differs from Matthew's but stands in dramatic tension with his own eschatology, as well as his previous interpretation of the parable of the sower. For the Markan harvest parable has no hint of an urgent crisis. Nor does it suggest concern about lost seed of any kind. Instead, it compares God's kingdom to a farmer who simply waits while the grain he sowed slowly matures until he can reap it. In sharp contrast to Mark's own presentation of Jesus' initial proclamation of God's kingdom [Mark 1:15], the Markan parable makes no claim that the time of harvest is at hand. So, the scene of automatic growth described by Mark 

• does not stress the Markan chronology of God's kingdom &
• lacks details of the crisis at the center of Matthew's parable of the weeds that are consistent with motifs that Mark himself stresses elsewhere.

And it is clearly independent of anything in Luke. Thus, the synoptic gospels' pattern of reporting these harvest parables fails to support the Griesbach source hypothesis. 

C	Did Luke use Matthew?

It is clearly easier to view Matthew's harvest parable as an editorial replacement for Mark's than vice versa. For, as noted in our prior analysis, Matthew's harvest parable is less problematic than Mark's as an analogy for the divine realm. So, it is easy to see why Matthew would have preferred a harvest parable that compares the kingdom of Heaven to a wise farmer rather than repeat the Markan parable, which likened God's kingdom to one who was ignorant. 

Also, the Matthean parable -- unlike its Markan parallel --  provides a good illustration of the eschatological views of the writer of the gospel in which it is recorded. For Matthew -- and only Matthew -- concludes Jesus' public preaching with another parable in which conflicting species are separated at the last judgment [Matt 25:31-46].  In that case "sheep" "inherit the kingdom" [25:34], while "goats" are cast "into the eternal fire prepared for the devil & his angels" [25:1].  Since it is clear that Matthew typically associated the divine kingdom with motifs of a final separation & a fiery consumption of those opposed to God, the fact that he alone reports the parable of the weeds presents no redactional problems.  

Thus, any source theory that regards the gospel of Matthew as a revision of Mark is better able to account for the variant harvest parables in these two gospels than a theory that views Mark as editor of Matthew.    

But what about Luke's source(s)? Since Luke reports neither the Markan nor the Matthean harvest parable, his narrative clearly does not follow either of the other synoptic gospels at this point. But  the question is whether Luke's silence at this point indicates his deliberate suppression of these parables.

In Luke, Jesus does not associate God's kingdom with either a period of waiting or a climactic separation of a select group from others are to be consumed. Rather, he publicly denies that the kingdom he envisions is marked by some dramatic future event:

Luke 17
20	Being asked by the Pharisees
	when the kingdom of God was coming,
	he answered them:
	"The kingdom of God is not coming with signs to be observed;
21	nor will they say, 'Look, here it is!' or 'There!'
	for, behold, the kingdom of God is in the midst of you."

Thus, Luke would have good reason not to copy Matthew's harvest parable, even if he knew it. 

The problem with this redactional scenario, however, is that one author's knowledge of another's text cannot simply be taken for granted. Rather, any theory of literary dependence needs to be demonstrated by a clear pattern of verbal agreement between documents, which is precisely what is lacking in this case. If it could be shown from surrounding passages that Luke's narrative was directly dependent on Matthew's version of these pericopes, then one might hazard a suggestion that he probably decided to omit the parable of the harvest, because it did not fit his interpretation of Jesus' proclamation of God's kingdom. But other explanations for an author's failure to reproduce a passage are possible, and in this case are more likely:

• either Luke did not use Matthew as a direct source; 

• or, if he did, his copy of Matthew did not contain this particular passage.

While it is true, that Luke's failure to cite the Matthean parable cannot be cited as evidence that he had no knowledge of it, it is just as true that his silence makes the opposite conclusion -- that he knew it but just chose not to report it -- unprovable.  Add to that, the fact that Luke's version of all the surrounding pericopes [Luke 8:4-18] is demonstrably closer to the parallel passages in Mark than to those in Matthew, and the simplest conclusion is that, for whatever reason, Luke did not use any material in this section of Matthew.

D	Are Matthew & Luke independent revisions of Mark?

The simplest way to account for the differences between the synoptic gospels in reporting these harvest parables is to assume that

• Mark wrote first &
• Matthew & Luke edited Mark without reference to each other's work.

Mark composed his gospel without a previous literary model by collecting originally independent oral chreiae & grouping them either by type or similar motifs. In previous chapters he strung healing & controversy stories together, while he devotes this segment of his narrative to Jesus' teaching in parables [Mark 4:2], which he associates with the message of God's kingdom [Mark 4:11].  The fact that the first parable Mark recalled focused on the figure of a sower scattering seed prompted him to recall a second parable that began with the same motif [Mark 4:26], even though this parable was not of  particular use in preparing readers for the imminent crisis that he usually associated with Jesus' proclamation of God's kingdom [see passages cited above].

In refining the Markan narrative, Matthew had already made several substantive revisions of this segment on parables before he came to this point, inserting several sayings to clarify the explanation of Jesus' use of parables [Matt 13:14ff] & omitting others (e.g., aphorisms of the lamp & the measure) that fit better in other contexts. He acted consistently, therefore, in omitting a parable that was theologically problematic (because it compared God's kingdom to a farmer who was ignorant of the processes of nature) & inserting another that explained the farmer's inaction between sowing & harvest.

Luke also decided to drop this parable & the surrounding sayings in his revision of Mark. But the fact that he failed to use Matthew's harvest parable makes it clear that his editorial activity was quite independent of any knowledge of the Matthean redaction of this passage.