This is how it is with the Kingdom of God;
it is as if a man were to scatter seed on the land
and would sleep and rise night and day
and the seed would sprout and grow,
he knows not how.
Usually we take comfort in the hidden growth of the Kingdom of God, and rightfully so. We can comfortably assume that such growth is in fact occurring even if we can't see it. Or at least we can if we are in fact scattering seed. Because it is especially the case that, since we know not how it works, scattering seed is an act of trust. This parabe is not one of mere passivity. It is about cooperation with a process of which we are only a small part. It's worth noting that we probably ought not to become too precious about the grain we help produce. After all, it seems to be very much the case that we're preparing it for the sickle, preparing it for death. After all, "unless a grain of wheat falls into the earth and dies, it remains alone; but if it dies, it bears much fruit" (see John 12:24).
It is like a mustard seed that, when it is sown in the ground,
is the smallest of all the seeds on the earth.
But once it is sown, it springs up and becomes the largest of plants
and puts forth large branches,
so that the birds of the sky can dwell in its shade.
The mustard seed doesn't seem start with the advantage it will have at the end, and appears to be the least likely thing to have such an advantage. We are therefore called to initially suspend our judgments based on preconceptions and appearances and trust what we know about the deeper worker of things. Because if what we want is something that can support all of the birds of the sky in its branches we will really have to trust these higher laws in order to begin with a mustard seed. Otherwise one would begin with nearly anything else. But such is the working of Jesus that if we cooperate with him and we trust him we can be confident of the results even when we can't yet see them.
Therefore, do not throw away your confidence;
it will have great recompense.
You need endurance to do the will of God and receive what he has promised.