Jesus talks of the Kingdom of heaven thus :
A man scatters seeds in his field. He goes to sleep in the night and is up and about during the day time, while the seeds are on their process of growing. Yet he is unaware of how it happens.
The soil, once the seeds are scattered, makes the plants grow and bear fruit. The tender stalk appears first, followed by the head and then the head, full with grains. When the grain is ripe, the man harvests it with his sickle, as the appropriate time or the harvest time has arrived.