Seeds are the source of our life. The seed is a mystery: both the beginning and the end, of life and death, of everything and nothing. In many cultures it has illustrated the spiritual journey and of moving from one season to another. If the species of a plant must continue, then its seed has to change, must be transformed, must lose its identity in order to become a new plant. If the seed is kept safe and secure, and not get cast into the soil, then it's going to be ineffective and not bring forth anything new.
The harvest grain represented both sources of food to sustain us during the coming winter months, but also the premise of hope for the Spring.