Dear 100 Hour Board,
If I'm not mistaken, there are only three references to the Sabbath in the Book of Mormon:
Jarom 1:5 - a statement that the people of Nephi had observed the Sabbath
Mosiah 13 - in which the 10 commandments are quoted
Mosiah 18:23 - a statement that Alma told the people baptized at the waters of Mormon to observe the Sabbath
To me, this seems like a disproportionately low amount of verses in the Book of Mormon about the Sabbath, especially since Christ taught some great doctrine about the Sabbath in the Gospels which the descendants of Lehi wouldn't have had access to. Why do you think that is/what do you make of it (if anything)?
-My Name Here
I might not have a full answer to this, but my first thought was that some of my favorite scriptures about the soul of the Sabbath are in the Book of Mormon, but weren't on your list. That's only because the word "Sabbath" doesn't occur in the chapter. Moroni 6 is one of my favorite chapters about why we have the church, and by extension, why we have the Sabbath. It's a beautiful passage about what the church is meant to do, why we have such a social aspect to the church, and why we meet together as a church.
Also, Christ taught a lot about the Sabbath because the Jews at the time had a concept of the Sabbath that Christ deemed as hypocritical. The New Testament includes a lot of rhetoric on the Sabbath Day because it was not well understood by the people that Christ was teaching. The people of Book of Mormon times certainly had problems that needed to be addressed, but it seems that the Sabbath day was not one that was as important for them. But, like I said, there are important scriptures about the role of the church, and about many things pertaining to the Sabbath. Maybe just not as explicitly as in the Bible.
Keep it real,