"The entire vision" probably refers to the whole Book of Isaiah. [1] God would hide His will from those who could know it but did not have the spiritual discernment to understand it. This would lead the people to appeal for an interpretation of His will for those who did not even have the intellectual ability to understand it. In other words, God would hide His plans from the people completely because all of them were spiritually obtuse, the literate and the illiterate. [source][source][source]