People could understand parables
As He talked, anyone listening could clearly relate to the idea of a farmer of that day spreading seed corn on his fields in the spring, hopeful of a good harvest in the fall.
Jesus drew that picture for the crowed, clearly fixing in their minds a much deeper lesson. In fact, as He prepared to reveal this truth to them, He said,
“Blessed, happy and fortunate are your eyes because they do see, and your ears because they do hear. Truly I tell you, many prophets and righteous men who were upright and in right standing with God yearned to see what you see. But they did not see and did not hear.
What Jesus was saying was that he was about to teach them something of enormous significance. He was about to unveil a truth that even Isaiah, Jeremiah, Ezekiel and Daniel had never heard or understood.