In this passage the text appears to unnecessarily repeat “and dwelt in tents”. In seven other places in the text, there are references to dwelling or living in tents. In no instance does the text first refer to dwelling in tents and then repeat this statement about tent dwelling while adding some specifi- cation about where the dwelling took place (as here in the current text for Ether 2:13). But there are three places where the text states, all within the same clause, that someone dwelt in a tent in a specific place (namely, Lehi dwelt in a tent in the valley of Lemuel):
Here in Ether 2:13 Oliver Cowdery seems to have once more created a dittography while copying from the original into the printer’s manuscript. We have already seen evidence for this kind of accidental dittography in the earliest extant text; for each of these dittographies, 𝓞 is not extant but probably read without the dittography:
In the last case, spacing between extant fragments of 𝓞 argues that 𝓞 read without the dittography. (See under each of these passages for the complete argument that a dittography has occurred.) The earliest extant reading here in Ether 2:13 (“and they dwelt in tents and dwelt in tents upon the seashore”) is similar to the three other examples of uncorrected dittography; in particular, each repetition begins with a repeated and. For all four of these cases of uncorrected dittography in 𝓟, the error probably occurred when Oliver copied the text from 𝓞 into 𝓟. Under Mosiah 10:5, I provide a list of cases where Oliver initially repeated an and- initial phrase but caught his error and crossed out the dittography.
Summary: Remove the apparent dittography in Ether 2:13 by deleting the extra “and dwelt in tents”, thus giving “and they dwelt in tents upon the seashore”.