Isaiah 49:24 (King James Bible)
shall the prey be taken from the mighty or the lawful captive delivered
The ink level for this correction in the original manuscript seems to indicate an immediate correction. The level of ink flow for first part of the supralinear for is unchanged, but slightly more ink flow occurs at the end of the word as well as for the insert mark, which may indicate that Oliver Cowdery redipped his quill while making this correction.
The corresponding King James passage does not have the for, so one could interpret the supralinear for as Joseph Smith’s decision to edit the King James text as he was translating. However, evidence elsewhere suggests that the Book of Mormon often has the connecting for when the King James Bible lacks it. Consider these examples from 1 Nephi 20–21:
In these three examples, the text in 𝓞 shows no correction: in each case, the connecting for was there from the beginning—that is, when Oliver Cowdery first took down Joseph Smith’s dictation. Yet in each case the for is missing from the King James passage. Also note that in both 1 Nephi 21:15 and 1 Nephi 21:24, the connecting for is placed before a yes-no question. In all of these cases, the difference between the two texts seems to be intentional. Moreover, the use of the for is consistent with the Book of Mormon’s tendency to increase the connectiveness of the text (see, for instance, the increased use of and in 1 Nephi 20:12–13).
Additional evidence for the connecting for here in 1 Nephi 21:24 is that it also appears later on in 2 Nephi 6 when Isaiah 49:24 is quoted a second time:
Thus the Book of Mormon tendency to insert for before yes-no questions in Isaiah quotes seems to be quite strong.
Summary: Maintain in 1 Nephi 21:24 the connecting for that was immediately added in the original manuscript; the difference here with the King James Bible parallels the extra for found elsewhere in the Book of Mormon’s Isaiah quotes.