2 Nephi 29:1-2 - What does this verse mean when looking at the phrase ". . . when I shall proceed to do a marvelous work . . ."?

There is an editing technique called "parsing" that allows the reader to analyze specific clauses of a text and how those clauses modify each other. Each clause touching the left side of the margin is viewed as an independent clause, independent of previous clauses. Clauses that don't touch the left side of the margin modify the clause above them.
I was interested in analyzing 2 Nephi 29:1-2 to see how punctuation affects the meaning of the verses.


     But behold, 
there shall be many—
at that day 


Why is there an em dash after many?
In the above parsing interpretation, at that day does not modify many; rather it begins a whole new idea independent of there shall be many because of the em dash. But I would interpret the verse as shown below (where at that day and the clauses that follow refer back to many. This way, the questions of "who" many refers to and "when" there shall be many are answered):



     But behold,
there shall be many—
                         at that day
                                     when I shall proceed to do a marvelous work 
                                                                                         among them, 
                                                   that I may remember my covenants 
                                                                                     which I have made unto the children of men, 
                                                   that I may set my hand again 
                                                                                       the second time 
                                                                           to recover my people, 
                                                                                                    which are of the house of Israel;


Here, the em dash places greater emphasis on the content of the verse after there shall be many. In Royal Skousen's book, The Book of Mormon: The Earliest Text, Skousen states that John Gilbert, who added punctuation to the 1830 edition of the Book of Mormon, added more punctuation than is probably necessary for modern writing (xlii). Skousen's interpretation of 2 Nephi 29:1 takes out the em dash after there shall be many to clarify the meaning of the verse. Perhaps Gilbert, when he put in the punctuation, thought that it was important to emphasize the fact that many people will be present at that day when Christ performs a marvelous work. This verse shows that there is hope for many of us.

Verse two is a continuation of verse one, where that I may remember the promises modifies the phrase, I shall proceed to do a marvelous work.

 2And also,
                                                   that I may remember the promises
                                                                                          which I have made unto thee, Nephi,
                                                                                                             and also unto thy father,
                                                                                          that I would remember your seed;
                                            and that the words of your seed should proceed forth
                                                                                                                                 out of my mouth 
                                                                                                                                 unto your seed;
and my words shall hiss forth
                                     unto the ends of the earth,
                                     for a standard unto my people,
                                                                                which are of the house of Israel;

It is a neat discovery to see that there are several reasons that Christ will proceed to do a marvelous work and a wonder. He will do a marvelous work 1) that He may remember His covenants which He has made unto the children of men, 2) that He may set His hand again the second time to recover His people, which are of the house of Israel, 3) that He may remember the promises which He has made that He would remember the seed of Nephi, and 4) that the words of Nephi's seed should proceed forth out of God's mouth unto Nephi's seed.

Because of these results, God's words shall "hiss forth unto the ends of the earth, for a standard unto my people, which are of the house of Israel."