“In the year that king Uzziah died, I saw also the Lord sitting upon a throne, high and lifted up, and his train filled the temple.” (2 Nephi 16:1) Here Isaiah sees the Lord and his sins are forgiven. Isaiah is called by the Lord to prophesy and he does, prophesying of the day of the Lord. Isaiah speaks about the pre-mortal world where Jesus Christ volunteered to be our Savior.
“…I heard the voice of the Lord, saying: Whom shall I send, and who will go for us? Then I said: Here am I; send me. And he said: Go and tell this people—Hear ye indeed, but they understood not; and see ye indeed, but they perceived not.” (2 Nephi 16:8-9)
Isaiah knew that the Lord would be persecuted and would be rejected, and he prophesies of this!