Isaiah 51:15–16 (King James Bible) but I am the LORD thy God that divided the sea whose waves roared the LORD of Hosts is his name and I have put my words in thy mouth
In the Book of Mormon text for 2 Nephi 8, verses 15–16 are consistently in the voice of the Lord (and in the first person), while in the King James Bible, a single clause is inexplicably in the third person (“the LORD of Hosts is his name). The Book of Mormon text smoothes out this wrinkle in the Isaiah text by replacing “his name” with “my name”. In fact, the Book of Mormon reading agrees with the Septuagint (Greek) and Vulgate (Latin) translations of the Hebrew for Isaiah 51:15; they both read “the Lord of Hosts is my name”.
It is quite possible that the Book of Mormon text and the Greek and Latin translations actually represent the original biblical text for Isaiah 51:15. The standard Hebrew text may be the result of a single word-final letter difference between ˇsÍm¯ı ‘my name’ and ˇsÍmo¯ ‘his name’—namely, a yod at the end of the first and a waw at the end of the second. These two letters are very similar in the standard square Hebrew script but considerably less so in the earlier paleo-Hebrew script.
Another factor that could have led to the his in the Hebrew text is that the expected biblical phraseology is “the Lord of Hosts is his name”. Except for possibly here in Isaiah 51:15, there are no occurrences in the biblical text of “the Lord of Hosts is my name”, but the reading with his occurs eight other times in the Hebrew Bible, five times in Jeremiah and three more times in Isaiah (here given in the King James translation):
The last two instances are also quoted in the Book of Mormon (in 1 Nephi 20:2 and 3 Nephi 22:5) and with the expected reading “his name”. In these other occurrences, the use of his is appropriate since it is the prophet who is speaking rather than the Lord. But in Isaiah 51:15, the speaker is the Lord himself, thus the appropriateness but uniqueness of “the Lord of Hosts is my name”.
Summary: Accept the use of my instead of his in 2 Nephi 8:15 (“the Lord of Hosts is my name”); the Lord is the speaker in this passage, so the use of my is wholly appropriate; the Hebrew text for Isaiah 51:15 has “his name”, but this reading is probably due to an early scribal error in the Hebrew.