Malachi 3:7 (King James Bible)return unto me and I will return unto you saith the LORD of Hosts but ye said wherein shall we return
The 1920 LDS edition introduced the present-tense reading say in 3 Nephi 24:7, even though Malachi 3:7 in the King James Bible has said. The change to say was intentional since it is marked in the 1920 committee copy. Perhaps the reason for making this change is that in the next verse the text reads in the present tense for the verb say:
In fact, the Hebrew original reads the same in both verses, as wa aÿmartem, which is translated in 20th-century conservative translations, such as the Revised Standard Version, as the present-tense you say. The parallelism is intended in the original Hebrew, and the 1920 LDS emendation brings out that parallelism in the Book of Mormon quotation.
Nonetheless, this kind of editing of a biblical quote is quite unusual for the Book of Mormon. Normally, Book of Mormon editing corrects an obvious difficulty or ungrammaticality. But here in 3 Nephi 24:7, there is no strong grammatical reason to do so except for the parallelism with verse 8. If such an emendation is accepted, one could probably find many biblical phrases in the Book of Mormon that could be changed. The biblical quotes in the Book of Mormon definitely follow the King James reading, even when the King James translation is not very felicitous. The critical text will restore the original reading ye said in 3 Nephi 24:7 (which agrees with the corresponding King James reading).
Summary: Restore in 3 Nephi 24:7 the original reading ye said (which agrees with the King James reading in Malachi 3:7); even though ye said clashes with ye say in the next verse, the Book of Mormon quotations from the King James Bible normally follow the specific language of that translation.