In the time of Jesus large cities like Jerusalem and some smaller towns had markets where people could go to vendors who brought their produce, fish and meats to a stall to be sold. Typically, each stall sold one item, such as fruits, vegetables, nuts, grains, spices, fish, meat etc. Outside of the large cities and towns people cultivated the items they wanted to eat on trees, bushes, stalks. When they were ready to eat, they picked what they wanted for that meal. So the people who followed and listened to Jesus were well aware of the importance of removing whatever did not produce good food and replace it with something that bears “good fruit.” The people who heard Jesus had no doubt about what he meant. And when he said, “A good person out of the store of goodness in his heart produces good, but an evil person out of a store of evil produces evil; for from the fullness of the heart the mouth speaks” they knew he was challenging them to choose good, not evil; to do right, not wrong; that God would judge them by what they produced.