It reads to me like He's sending Isaiah.
That could be plausible, except for two things:
1.) He refers to himself as the "LORD, thy Redeemer, the Holy One of Israel", and
2.) In verses 12 and 13 where the same person is speaking he is called the "first and the last" and the one who "laid the foundations of the earth."
Isaiah was a great prophet, but he wasn't that great.