Matt 13:24-43

PARABLES OF THE KINGDOM
Here in this Chapter, Jesus gives us three parables that explain the growth, corruption, and purification of the kingdom of heaven.
The Parable of the Tares
24 He set another parable before them, saying, “The Kingdom of Heaven is like a man who sowed good seed in his field, 25 but while people slept, his enemy came and sowed darnel also among the wheat, and went away. 26 But when the blade sprang up and brought forth fruit, then the darnel appeared also. 27 The servants of the householder came and said to him, ‘Sir, didn’t you sow good seed in your field? Where did this darnel come from?’ 28 He said to them, ‘An enemy has done this.’ The servants asked him, ‘Do you want us to go and gather them up?’ 29 But he said, ‘No, lest perhaps while you gather up the darnel, you root up the wheat with them. 30 Let both grow together until the harvest, and in the harvest time I will tell the reapers, “First, gather up the darnel, and bind them in bundles to burn them; but gather the wheat into my barn.”‘” 
Matt 13:29
the wheat and tares – the good and bad grow up until the time of the harvest. The time of the harvest will be described as the end of the age, when the lawless are removed from the kingdom of heaven. The harvest in Rev 14:18 is described as a harvest of grapes.  
The Parable of the Mustard Seed
31 He set another parable before them, saying, “The Kingdom of Heaven is like a grain of mustard seed, which a man took, and sowed in his field; 32 which indeed is smaller than all seeds. But when it is grown, it is greater than the herbs, and becomes a tree, so that the birds of the air come and lodge in its branches.” 
Matt 13:31
the mustard seed – the growth of the kingdom of heaven will be great. The birds of the air were described as the workers of Satan in verse 4 and 19. The phrase “birds of the air come and rest in its branches” is from Dan 4:12, where it describes the kingdom of the beast, the corrupted kingdom of heaven. The reason for that corruption is described in the next parable.
The Parable of Leavened Kingdom
33 He spoke another parable to them. “The Kingdom of Heaven is like yeast, which a woman took, and hid in three measures of meal, until it was all leavened.”
Matt 13:33
the kingdom of heaven is like a leaven – Jesus described the false teachings of the Pharisees as leaven, see Matt 16:6. Leaven represents falsity. Paul told us that we eat the “unleavened bread of sincerity and truth” (1 Cor 5:8). The unleavened flour represents “unleavened truth,” and the leavening of the flour represents the corruption of the truth.

a woman – the woman is the Great Harlot in Revelation.

three measures of meal – most commentators recognize the the expression “three measures” is not arbitrary, and that there must have been some specific reason for the number three. But, they cannot determine what the reason for three is. Here, we need some careful thought.

The Greek expression here is “ἀλεύρου σάτα τρία” (flour, measures, three). The Greek word σάτα, sata, actually comes from the Hebrew word “seah” meaning “measure.” We find the same expression, “three measures of meal” in Gen 18:6.  The word “seah” can also define a specific quantity of dry flour, but the primary meaning is simply “measures” or “measurements.”

The measurements of the true Church are the measurements of truth, these are the three measures of unleavened flour. In Ezek 43:10-11, we learn that these “measurements must be strictly adhered to.”

The Bible gives us three measures of doctrine that must be adhered to, in order to be saved.

① We must “know…the one true God” (John 17:3).
② We must “obey the Gospel of Jesus Christ,”  (2 Thess 1:8). This includes the need to be baptized and remember Christ’s death “in like manner” to Christ, and the Apostles.
③ We must do the will of God, and keep His commandments (Matt 7:21).

The leavening of the true measurements came by Tertullian, in A.D. 190. He was the father of Latin Christianity, whose number is 666 (lateinos). He corrupted the “three measurements” of truth.

① He proposed the Trinity in his tract Against Praxeas.
② He discounted the need to baptize “in like manner,” in living water in his tract On Baptism. The need to baptize “in like manner,” in living water, was recognized by Justin Martyr and the Church in A.D. 150, as we read in Justin Martyr’s First Apology.
③ He said that the Sabbath was a temporary commandment in his book An Answer to the Jews.
34 Jesus spoke all these things in parables to the multitudes; and without a parable, he didn’t speak to them, 35 that it might be fulfilled which was spoken through the prophet, saying, “I will open my mouth in parables; I will utter things hidden from the foundation of the world.” 
Matt 13:34
He did not speak without a parable – see also Matt 13:11, the secrets of the kingdom are only for His disciples to understand.
The Parable of the Tares Explained
36 Then Jesus sent the multitudes away, and went into the house. His disciples came to him, saying, “Explain to us the parable of the darnel of the field.” 37 He answered them, “He who sows the good seed is the Son of Man, 38 the field is the world; and the good seed, these are the sons of the kingdom; and the darnel are the sons of the evil one.39 The enemy who sowed them is the devil. The harvest is the end of the age, and the reapers are angels. 
the parable of the tares – the good and bad grow up together in the kingdom of heaven. Jesus warned us that there would be wolves among the sheep. The wolves, or robbers, described in John 10, are those who will pervert the Gospel, speaking “perverse things,” as Paul tells us in Acts 20:29-30.
40 As therefore the darnel is gathered up and burned with fire; so will it be in the end of this age. 41 The Son of Man will send forth his angels, and they will gather out of his kingdom all things that cause stumbling, and those who do iniquity, 
Matt 13:41
The Son of Man will send forth His Angels – this parable will be described in Revelation Chapters 8, 14, 16, and 19 where we see the Angels who remove the lawlessness from the kingdom.
42 and will cast them into the furnace of fire. There will be weeping and the gnashing of teeth. 43 Then the righteous will shine forth as the sun in the kingdom of their Father. He who has ears to hear, let him hear. 
Matt 13:42
cast them into the furnace of fire – as described in Rev 14:10.

shine forth as the sun – the Spirit of Christ, as the Body of Christ, will shine forth as the sun, see Rev 16:8.