LDS Institute Manual's Introduction to Isaiah.
"Understanding Isaiah," Old Testament Student Manual:1 Kings–Malachi (Salt Lake City: The Church of Jesus Christ of Latter-day Saints, 1981), 131
(E-1) The Importance of Isaiah’s Writings
Isaiah’s name means “Jehovah saves” or “the Lord is salvation.” His life and teachings proclaim the message of Christ and the way of salvation Christ provided. John wrote that “the testimony of Jesus is the spirit of prophecy” (Revelation 19:10). Using that statement as a criterion to evaluate, we must classify Isaiah among the greatest of the prophets, because he powerfully and eloquently testified of Christ and His work.
The Savior Himself affirmed the importance of Isaiah’s writings when, in His visit to the Nephites, He commanded them to search diligently the words of Isaiah (see 3 Nephi 20:11). The Lord said, “Great are the words of Isaiah. For surely he spake as touching all things concerning my people which are of the house of Israel” (3 Nephi 23:1–2). The words Jacob spoke to his people can also be applied to us. Jacob said, “There are many things which have been spoken by Isaiah which may be likened unto you, because ye are of the house of Israel” (2 Nephi 6:5). We also are of the house of Israel.
The writings of Isaiah are quoted extensively in other scripture. In fact, Isaiah is quoted in other scriptures more often than any other prophet. There are sixty-six chapters in the book of Isaiah, making a total of 1,292 verses. The prophets in the Book of Mormon quoted 414 of those verses (32 percent of the book of Isaiah). They paraphrased at least another 34 verses (3 percent). The Nephite prophets considered Isaiah’s writings to be of such great worth that they put approximately 35 percent of the book of Isaiah in the valuable space they had on the plates. The writers of the New Testament had a similar respect for Isaiah’s teachings and prophecies. In the New Testament, Isaiah is quoted at least fifty-seven times.
In latter-day revelation there is a similar emphasis on the words of Isaiah. The Doctrine and Covenants makes approximately one hundred references to Isaiah’s writings by quoting, paraphrasing, or interpreting his teachings. The close connection between Isaiah’s words and those of the Doctrine and Covenants is apparent in Doctrine and Covenants 113, which contains inspired interpretations of chapters 11 and 52 of Isaiah. The key to understanding Isaiah 65 is in Doctrine and Covenants 101; Doctrine and Covenants 133 opens up an understanding of Isaiah 35, 51, 63, and 64. Numerous examples of Isaiah’s phraseology can be found in the Doctrine and Covenants; compare Doctrine and Covenants 133:3, 15, 27, 40–53, 67–70with Isaiah 52:10, 12; 51:10; 64:1–4; 63:1–9; 50:2–3, 11.
The prophet Nephi said that Isaiah spoke many things that were hard for his people to understand (see 2 Nephi 25:1). The same is true of people today. Even among the Saints who have the gift of the Holy Ghost there are many who understand very little of what Isaiah taught. Elder Bruce R. McConkie wrote:
“If, as many suppose, Isaiah ranks with the most difficult of the prophets to understand, his words are also among the most important for us to know and ponder. …
“… His prophetic words can and should shine brightly in the heart of every member of the Church.” (“Ten Keys to Understanding Isaiah,” Ensign, Oct. 1973, p. 80.)
Nephi studied, expounded upon, and loved the writings of Isaiah (see 2 Nephi 11:8; 12–24; 25:1–5). Concerning our need to understand Isaiah as Nephi did, Elder McConkie said: “It just may be that my salvation (and yours also!) does in fact depend upon our ability to understand the writings of Isaiah as fully and truly as Nephi understood them” (“Ten Keys to Understanding Isaiah,” p. 78).
Elder McConkie explained that if we desire to go where Isaiah and Nephi have gone, then we must believe, think, know, teach, and live as they did. Certainly the writings of Isaiah deserve our careful and prayerful study. They can be understood by those who sincerely desire to do so.
(E-2) Keys to Understanding Isaiah
For those who sincerely desire to understand the writings of Isaiah, several keys are helpful. Through the use of these keys, individuals can gain great insight into Isaiah’s teachings and can grow in the knowledge of the truth until the writings of Isaiah become as clear to them as they were to Nephi. These keys are discussed below.