The text that Jesus Christ dictates in Chapter 25 of the Third Book of Nephi is virtually indistinguishable, word for word, from Chapter 4 of Malachi from the Old Testament.
“The day of judgment is coming,” said God to Malachi, “and the proud and wicked will be burned up like straw in the oven. But for those who fear my name, the Son of Righteousness will rise up with healing wings like calves let loose in the pasture. The wicked will be trampled like ashes underfoot. Remember to abide by the laws that I gave my servant Moses. I will send you Elijah the prophet before the great and terrible day of judgment. He will turn the hearts of fathers to children, and children to fathers, or I will destroy the earth with my curse.”