KJV Errors in the Book of Mormon
When quoting passages from Isaiah in the Book of Mormon, Joseph Smith relied on the English King James version (KJV) of the Bible. Since Nephi would have relied on the Isaiah passages on the brass plates of Laban, doesn’t Joseph Smith’s use of the KJV suggest that he did not really translate from an ancient record? In relying on the KJV translation, he even preserved some of the mistakes made by its translators.
It is likely that the prophet would also have been criticized had his translation of the Isaiah passages read differently from that of the KJV, which was the Bible most commonly used in his day. Employing KJV language made it possible to correlate Book of Mormon quotes with those of the biblical Isaiah already available to readers.
Virtually every Old Testament quote in the New Testament, including passages from Isaiah, is drawn not from the Hebrew text, but from the Greek Septuagint (abbreviated LXX), translated in the second or third century BC. Even when the Septuagint is an incorrect translation, it is used by the New Testament writers. Similarly, when Joseph Smith dealt with the Bible quotes in the Book of Mormon, he relied on the most widely-used English translation of the day, the KJV, even when it contained errors. It is true that he made some changes, but New Testament writers often did that as well, while relying on the LXX text.
One of the errors found in KJV is In Isaiah 5:25, where the translators’ rendering “torn” is clearly wrong, and the more modern reading “their carcases shall be like garbage” is logical. The Hebrew word appears only in this passage, which makes it a hapax legomenon whose meaning cannot be fully ascertained without further corroboration.
A supposed error occurs in Isaiah 4:5, where the Hebrew word huppāh is rendered “defense.” Critics note that modern translations render it “covering.” The term is found only three times in the Bible; in Psalm 19:5, KJV renders it “chamber” (“as a bridegroom coming out of his chamber”), while in Joel 2:16 it is rendered “closet” (“let the bridegroom go forth of his chamber, and the bride out of her closet”), while a different word is used for “chamber.”The verbal form of the Hebrew root means “to hide,” which cannot be done by standing underneath a canopy; it would have to be in a closed space (or, in KJV terminology, “closet”). Consequently, there is no real problem with the KJV rendering of “defence.”
For more information, see John A. Tvedtnes and Matthew Roper, “‘Joseph Smith’s Use of the Apocrypha’: Shadow or Reality?” in Review of Books on The Book of Mormon 8/2 (1996). For reasons why Joseph Smith used KJV language in his translation of the Book of Mormon, see John A.Tvedtnes, Defining the Word: Understanding the History and Language of the Bible (American Fork: Covenant, 2006).
 The last two are the basis of the Jewish practice of performing weddings with the bride and bridegroom standing beneath a canopy, but this practice is not attested in antiquity.
 When Jesus said that one should pray in a “closet” (Matthew 6:6), he did not have reference to a small room where one hangs clothes, for such did not exist in his day or, indeed, until recent times. Rather, he had reference to an enclosed space where one could not be seen to pray in public.