“For beholde, I will send you Eliiah the prophet before the comming of the great and dreadfull day of the LORD.”

Malachi 4:5 (AKJV – 1611 edition)

“Behold, I will reveal unto you the Priesthood, by the hand of Elijah the prophet, before the coming of the great and dreadful day of the Lord.”

Doctrine and Covenants (Salt Lake City, UT: The Church of Jesus Christ of Latter-day Saints, about 1820), 2:1.