In the 19th century, the two verbs sit and set were frequently mixed up in their forms. Even today some speakers have difficulty with these verbs. Historically, sit is intransitive and takes sat as the simple past and past participle, while set is transitive and takes the identical set as the simple past and past participle. (See the discussion under set, sit in Merriam-Webster’s Dictionary of English Usage.)
Here in 1 Nephi 11:1, the earliest editions retained the sat of the original manuscript. The change to the standard set was first made in the 1849 LDS edition and then independently in the 1858 Wright edition; the standard set has been followed in all subsequent editions.
It is possible here that the original manuscript’s sat is an accident. The previous use of sat earlier on in the verse (“as I sat pondering”) may have influenced the choice of sat near the end of the verse. Nonetheless, the tendency to mix up the two verbs sit and set is found throughout the Book of Mormon text. Out of a total of 105 cases, the earliest textual sources show 10 examples of nonstandard usage. (For a complete list, see sit in volume 3.) Since the frequency of this usage was very high in the 19th century, we will assume that the occasional mix-up in the text is intended. Thus for 1 Nephi 11:1, we follow the earliest textual sources that support sat, even if this particular occurrence could be due to scribal error.
Summary: Based on the earliest textual sources, the dialectal sat (in 1 Nephi 11:1) will be restored in the critical text; mix-ups between the intransitive sit and the transitive set occur about 10 percent of the time in the text.