Isaiah next appealed to his audience, the people of Jerusalem and Judah, speaking for his well-beloved (God). He asked them for their opinion. What more could he have done to ensure a good crop? Why did his vines produce worthless (sour) grapes? In view of what the owner had done ( Isaiah 5:1-2), the answers would have to be: "You could have done nothing more than you did," and: "The grapes were the cause of the disappointment, not you."[source]