Just as Matthew presents the purpose for Jesus' opaque teachings (vv. 10-17) in the midst of a parable explaining that not all will receive the gospel and persevere for him (vv. 3-9, 18-23), he now presents the parables of the mustard seed and the yeast (vv. 31-33) in the midst of the parable of the weeds (vv. 24-30, 36-43), with more words about the nature of parables (vv. 34-35). The parable of the weeds (vv. 24-30, 36-40) emphasizes that children of the kingdom must coexist with children of the evil one in this world until their vindication at the end. The parable may also reinforce images of conversion, perseverance and apostasy in the parable of the sower (vv. 3-9, 18-23): especially in places where disciples can blend into the world (v. 22), it is hard to know for sure who will persevere until the final judgment. The glorious kingdom of the future is present in this age only in an obscure and hidden way, except to those with eyes of faith (vv. 31-33).