The message is presented in the form of an introverted parallelism, or chiasm:
a Make the heart of this people fat,
b and make their ears heavy,
c and shut their eyes—
c lest they see with their eyes,
b and hear with their ears,
a and understand with their heart
For more light on the rejection of the prophetic call to repent, compare Zechariah 7:11–12; Matthew 13:10–17; Jacob 4:14; Alma 12:9–11; and 3 Nephi 18:32. Isaiah was instructed to make the true doctrine so plain that his people would have to accept it or harden their hearts against it. The same would happen in these last days.
Question: Why would the Lord send a prophet to a people he knew would reject the message? Answer: (1) as a warning to them and to us in the latter-days, (2) as a testimony or witness against them, (3) so people could prove themselves to themselves, and (4) some would believe, and they would be grateful to Isaiah.