We are told that there was a prophecy in the destruction of the coat of many colors worn by Joseph. Part of it was preserved, and Jacob, before his death, prophesied that as a remnant of the coat was preserved so should a remnant of Joseph’s posterity be preserved.
‘And he said, Even as this remnant of garment of my son’s hath been preserved, so shall a remnant of the seed of my son be preserved by the hand of God, and be taken unto himself, while the remainder of the seed of Joseph shall perish, even as the remnant of his garment.’—
Alma 46:24.
“That remnant now found among the Lamanites shall eventually partake of the blessings of the Gospel. They shall unite with the remnant which is being gathered from among the nations and they shall be blessed of the Lord forever.
(Joseph Fielding Smith, The Way to Perfection, p. 121)