This verse continues the theme of reversal. The deaf will hear and the blind will see. Deafness and blindness may be images for disobedience, which will come to an end. However, real deaf and blind people may be in view here, so translators should render this verse nonfiguratively. They may refer to a possible figurative meaning in a footnote.
In that day is a standard prophetic phrase referring to a general time in the future (see the comments on 2.11)
The deaf shall hear the words of a book: This clause assumes that someone is reading from a book and that the deaf are now able to hear it. Translators may need to clarify this by saying “the deaf will hear the words of a book that someone is reading.” The deaf renders a plural expression in Hebrew, so it refers to any deaf people. The phrase the words of a book occurred earlier in verse 11. Thus the book that was sealed and could not be read (verses 11-12) will now be opened and read. More importantly, the deaf will be able to hear what is read from it.
And out of their gloom and darkness the eyes of the blind shall see: Not only will the deaf hear, but the blind will see. Gloom and darkness describes the state of a blind person, living in a world of shadows and darkness. The Hebrew word for gloom normally refers to the presence of very little light rather than the absence of all light. Here it is in a word pair with darkness. Translators can choose two similar terms that go together naturally. The important point here is that the blind will see. The blind refers to any blind people.
For the translation of this verse we can say:
• At that time, the deaf will hear someone read a book,
and the blind will see and no longer live in shadows and darkness.
• At that time, when someone reads a book,
any deaf person will be able to hear it,
and any blind person will be able to see
and no longer live in gloom and darkness.
Quoted with permission from Ogden, Graham S. and Sterk, Jan. A Handbook on Isaiah. (UBS Helps for Translators). New York: UBS, 2011. For this and other handbooks for translators see here .