13:24 kingdom of heaven. On the meaning of “the kingdom of heaven,” see note on Matthew 3:2. The earthly aspect of God’s kingdom (essentially churches and other organizations participating in the work of the kingdom in the name of Christ) is in view here, since its constituencies include false Christians as well as true believers. From the preceding parable, it seems that both emotional believers and worldly believers (Matthew 13:20-22) may provide the “soil” in which the “tares” sown by the enemy can thrive, in which the “leaven” of false doctrine can spread (Matthew 13:33) and “birds of the air” that devour the good seed can lodge (Matthew 13:32).
13:25 while men slept. Matthew implies that if believers were sufficiently alert and informed, the “tares” could never have infiltrated the wheat.
13:25 enemy. In this parable, “the enemy” represents the devil, and “He that soweth good seed is the Son of man (Matthew 13:37,39).
13:29 also the wheat. Evidently it is impossible for anyone but the Lord Himself to distinguish unfruitful believers in the kingdom from false believers. Even the latter may not realize they are actually unsaved. Thus Peter warns those that are “barren” or “unfruitful” in Christ to “give diligence to make your calling and election sure” (II Peter 1:8,10).