Is Isaiah 6 about hardening?

Isaiah 6:9-10 says: And He said, "Go, and tell this people: 'Keep on hearing, but do not understand; Keep on seeing, but do not perceive.'  "Make the heart of this people dull, And their ears heavy, And shut their eyes; Lest they see with their eyes, And hear with their ears, And understand with their heart, And return and be healed."

Many people, including Steve Hays (link) have taken this passage to be about divine hardening.  If it is, it's certainly no problem for Armininan theology, especially since hardening is typically the exception rather than the rule.  Further hardening is a punishment for past sins.  Also the passage does not say they cannot see or hear.  However, is this passage about hardening?

Isaiah never actually commands the people  “don’t understand”.  He never delivered this message as such.  So more than likely this is a case where a prophet is said to do what he foretells, like Jeremiah 1:10:

See, I have this day set you over the nations and over the kingdoms, To root out and to pull down, To destroy and to throw down, To build and to plant (Jeremiah 1:10).  Just as Jeremiah didn't destroy nations and kingdoms, so also, Isaiah did not tell the people not to understand.  Rather, Isaiah preached a message of repentance, warning the people of coming judgement.  But the foreseeable result of this message was that it would be rejected and Israel would not be healed.

Also, note the LXX and Acts 28 & Matthew 13 transform the command (keep on hearing, but do not understand) into a prediction (ye shall hear indeed, but ye shall not understand):

English translation of LXX of Isaiah 6: And I heard the voice of the Lord, saying, Whom shall I send, and who will go to this people? And I said, behold, I am here, send me. And he said, Go, and say to this people,

Ye shall hear indeed, but ye shall not understand; and ye shall see indeed, but ye shall not perceive.

For the heart of this people has become gross, and their ears are dull of hearing, and their eyes have they closed; lest they should see with their eyes, and hear with their ears, and understand with their heart, and be converted, and I should heal them.

Matthew 13:14 'Hearing you will hear and shall not understand, And seeing you will see and not perceive; For the hearts of this people have grown dull.  Their ears are hard of hearing, and their eyes they have closed, Lest they should see with their eyes and hear with their ears, Lest they should understand with their hears and turn, so that I should heal them.

Acts 28:26-27 Go to this people and say: hearing you will hear, and shall not understand; and seeing you will see and not perceive.  For the hearts of this people have grown dull.  Their ears are hard of hearing, and their eyes they have closed, Lest they should see with their eyes and hear with their ears, Lest they should understand with their hears and turn, so that I should heal them.

Similarly, the LXX, Mt 13 & Acts 28 have “so that I should heal them” or “let me heal them” instead of “least I should heal them”. So the passage is talking about the Jews lack of desire to be healed through repentance not God’s desire to not heal them.  

Differences between the Old Testament Hebrew and the New Testament quotations of the same passage can be tricky.  If one insists on a literal reading of the Old Testament, then the best way to square it with the New Testament quotations (without saying they are misquotes) is to say the Old Testament was using irony, like saying “the last thing they want is to see with their eyes and hear with their ears and for me to heal them.”  Job 12:2 is an example of irony in the bible.