"Divided hither and thither" -- a side note

I just finished a two-part series on the phrase "divided hither and thither" in Helaman 10:1 as an example of metalepsis.  As I studied, I noticed something else about this phrase that I'd like to touch on in this short post.

A puzzle regarding source material

It is very interesting to me that Elijah's story of parting the waters is an obvious example of metalepsis referring back to the story of Moses parting the Red Sea. That part seems pretty clear -- Elijah's actions are being compared to Moses' in a way that is intended to bring Moses' account into the mind of the reader -- Elijah is being directly compared to Moses. 

Here's the odd thing about this -- the Exodus account does not include the phrase "divid[ing] hither and thither" even though the Elijah account does. So if "divide hither and thither" was a key phrase in the mind of the author of 2 Kings 2, but Exodus lacks the phrase. 

Of note, the Book of Mormon contains three references to Moses parting the waters which include the key phrase "dividing/parting hither and thither" (see 1 Nephi 4:2, 1 Nephi 17:26, and Helaman 8:11). 

How can this be explained?

I see a few possibilities. 

1) Elijah was a northern kingdom prophet in the 9th century BC. It is possible the northern kingdom records made reference to Moses parting the Red Sea using the phrase "dividing hither and thither" but was left out of the current version of the Old Testament when records were combined and the southern kingdom account of Moses was given preference.

2) The first version of what we now call the "Old Testament" included the phrase "divided hither and thither" in the Moses account, but this was removed by redactors some time after Lehi left Jerusalem with the Brass Plates. (See diagram below.)

One possible explanation for the apparent difference in source material.

I don't know what happened, but it certainly is interesting that Nephi and Mormon seem to clearly link "divide hither and thither" with Moses even though we don't find that phrase in Exodus.