Why were the plates Joseph Smith transcribed written in Reformed Egyptian?
When Lehi and his family left Jerusalem (under duress) they went to great lengths to acquire the Brass Plates of Laban to take with them into the wilderness and on to the Promised Land. The Brass Plates were a very precious document. The Bible as we know it was very likely copied from the Brass Plates. However, the copiers only copied a part of the information that was on the Brass Plates.
This is what we are told that the Brass Plates contained—
–the Old Testament up to the time of Zedekiah, including the five books of Moses,
–the writings of prophets not mentioned in the Old Testament, such as Ezias, Neum, Zenock and Zenos.
–a record of the Jews and the prophecies of the holy prophets from the beginning, down to the commencement of the reign of Zedekiah, king of Judah;
–many prophecies which have been spoken by the mouth of Jeremiah.
–the writings of both Lehi and Jeremiah, who wrote their prophecies on the Brass Plates in the Egyptian language.
Why did Lehi and Jeremiah write on the Brass Plates in the Egyptian language? Simply because that was the language in which all the prophets before them had inscribed their records. Both Lehi and Mosiah taught their children to read Egyptian so that they could read and understand what was written on the Brass Plates. So Egyptian was the language of the scriptures among the Nephites for a thousand years. So when Mormon abridged the Brass Plates and Moroni abridged the 24 gold plates of Ether that gave the history of the Jaredites, they wrote their records also in the Egyptian language. However, Moroni gives a little added insight into why they did what they did. He said:
And now, behold, we have written this record according to our knowledge, in the characters which are called among us the reformed Egyptian, being handed down and altered by us, according to our manner of speech. And if our plates had been sufficiently large we should have written in Hebrew; but the Hebrew hath been altered by us also; and if we could have written in Hebrew, behold, ye would have had no imperfection in our record. (Morm 9:32-33)
He speaks of writing in a reformed Egyptian, and the reason was that as it was handed down over the thousand year period it had been altered according to their manner of speech. This is a very natural process. Shakespeare was born in the year 1564. If you were to read one of his plays, I’m sure that you would find it very difficult to understand because of the way our language has changed over that period of time. That’s about half the time that the Nephite prophets were recording their records in Egyptian, which was their second language. So Moroni didn’t really alter the Egyptian language. It was gradually changed by all of the writers who went before him. He undoubtedly wrote his Egyptian record much like his father, Mormon did. He just informs us that the language among them gradually changed over time.