This is an example of a Hebrew-like syntactic construction that was soon removed from the text. In the original text of the Book of Mormon, there are a number of examples where the conjunction and occurs between a preceding subordinate clause and its following independent clause. Such constructions are characteristic of Hebrew but not English. Over time these extra and ’s have been eliminated from the text. Here in 1 Nephi 8:13, we have such an and (following a sentenceinitial as-clause) which Oliver Cowdery deleted in the printer’s manuscript. He initially wrote an ampersand in agreement with the original manuscript’s And, but then he deleted the ampersand to make the text conform to English. Perhaps he thought the and in 𝓞 was some kind of scribal error. (The and in 𝓞 is capitalized because scribe 3 of 𝓞 often capitalized the first word in a handwritten line irrespective of its position in the sentence.)
The critical text will restore this Hebrew-like use of and after an initial subordinate clause. For further discussion of this type of construction, see hebraisms in volume 3.
Summary: Restore the original Hebraistic and ’s following initial subordinate clauses.