In brief parables the kingdom of God is likened to a mustardseed and to leaven.
He had announced the nearness of the kingdom of God, but had described it only in parables from nature.
He also pointedly alludes to John's work and the people's relation to it, in many sayings and parables (sometimes in a tone of irony).
It looks as if they were insertions in the passage as it originally stood, and that the references to parables in the plural, together with the statement at vv.
I am speaking particularly of the Beatitudes, sermon on the mount / plain, and the parables.