Why does it say that the deaf will hear?
Rashi: The curse above "Ki Nasach Hashem Aleichem", "va'Tehi Lachem Chazus ha'Kol", "v'Avdah Chachmas Chachamav (10-11, 14) will be nullified.
Radak: Those who were deaf will now come to hear the words of the Sefer. [Before,] they were blind from seeing them; they were "ha'Sefer he'Chasum" (11).
Malbim: The first group, which said that the Navi's words cannot be understood, like a sealed Sefer - they will hear and understand.
What is the meaning of "ume'Ofel ume'Choshech"?
Radak: From the affliction you will see the Nevu'ah fulfilled. They were blind about it when the Navi rebuked them.
Malbim: The second group, which said that Hashem does not see man's deeds in darkness - not only will they recognize that He knows and sees in darkness like light - also the eyes of the blind, he will give to them Nevu'ah, which does not depend on physical senses.
