“It should be remembered that the brass plates Nephi obtained contained the five books of Moses (see 1 Nephi 5:10–11). This record, which would have contained the Ten Commandments, had been passed down by Nephite prophets and record keepers. Evidently the contents of the brass plates were known to Noah and his priests because they quoted from Isaiah and referred to the law of Moses (see Mosiah 12:20–24, 28 )” (Book of Mormon Student Manual [1989], 63).