And the vision of all - The vision of all the prophets; that is, all the revelations which God has made to you (see the note at Isaiah 1:1). The prophet refers not only to his own communications, but to those of his contemporaries, and of all who had gone before him. The sense is, that although they had the communications which God had made to them, yet they did not understand them. They were as ignorant of their true nature as a man who can read is of the contents of a letter that is sealed up, or as a man who cannot read is of the contents of a book that is handed to him.
As the words of a book - Margin, ‘Letter.’ The word ספר sêpher may mean either. It properly means anything which is “written” (Deuteronomy 24:1, Deuteronomy 24:3; Jeremiah 32:11; Daniel 1:4), but is commonly applied to a book Exodus 17:14; Joshua 1:8; Joshua 8:34; Psalms 40:8.
That is sealed - (see the note at Isaiah 8:16).