According to latter-day revelation, Elijah held the sealing power of the Melchizedek Priesthood and was the last prophet to do so before the time of Jesus Christ. He appeared on the Mount of Transfiguration and conferred the keys on Peter, James and John. (See Matt. 17:3.) On April 3, 1836, he appeared in the Kirtland Temple and conferred the same keys upon Joseph Smith and Oliver Cowdery.
Source: Bible Dictionary, LDS edition of King James Bible, p. 664.
