In my post, Biblical Prophets Changing their Words and the Words of Previous Prophets, I discussed the biblical evidence showing that prophets can and have changed the text of their revelations and the text of previous prophets (e.g., Jeremiah; Isaiah; Moses), so there was nothing improper with Joseph Smith having done the same. In this post, I will briefly discuss one of the more interesting examples of Joseph having changed (or, to be more precise, expanded) a revelation, and offer a possible explanation underlying such.
Section 7 of the Doctrine and Covenants purports to be a translation of a parchment composed anciently by John, the beloved disciple. When one compares D&C 7 with section VI of the 1833 A Book of Commandments and the text in Revelation Book 1, one will find a number of expansions (text in red denotes additional material; text in black is original to the Book of Commandments/Revelation Book 1 text):
And the Lord said unto me: John, my beloved, what desirest thou? For if you shall ask what you will, it shall be granted unto you. And I said unto him: Lord, give unto me power over death, that I may live and bring souls unto thee. And the Lord said unto me: Verily, verily, I say unto thee, because thou desirest this thou shalt tarry until I come in my glory, and shalt prophesy before nations, kindreds, tongues and people. And for this cause the Lord said unto Peter: If I will that he tarry till I come, what is that to thee? For he desired of me that he might bring souls unto me, but thou desiredst that thou mightest speedily come unto me in my kingdom. I say unto thee, Peter, this was a good desire; but my beloved has desired that he might do more, or a greater work yet among men than what he has before done. Yea, he has undertaken a greater work; therefore I will make him as flaming fire and a ministering angel; he shall minister for those who shall be heirs of salvation who dwell on the earth. And I will make thee to minister for him and for thy brother James; and unto you three I will give this power and the keys of this ministry until I come. Verily I say unto you, ye shall both have according to your desires, for ye both joy in that which ye have desired.
Many, if not all, these changes, can be explained as the Prophet Joseph Smith expanding upon the subtext of the original translation of this parchment. What is “subtext”? Subtext is defined as "the unspoken or less obvious meaning or message in a literary composition, drama, speech, or conversation. The subtext comes to be known by the reader or audience over time, as it is not immediately or purposefully revealed by the story itself" (source). In the case of the first change we witness, the addition of “For if you shall ask what you will, it shall be granted unto you,” such can be seen as the subtext to the initial question of Jesus to John, showing it was not just a question posed only out of sheer curiosity, but implicitly bearing a promise of Jesus wishing to fulfil the desire of the disciple. The other expansions to the original revelation can be seen, too, as explicating the subtext.