Joseph Smith, and my father, Hyrum Smith, Brigham Young, John Taylor, Wilford Woodruff, and other choice spirits who were reserved to come forth in the fulness of times to take part in ... the building of the temples ... for the redemption of the dead, were also in the spirit world. Doctrine & Covenants 138:53
Trivia: What man in the Doctrine and Covenants is said to be a perfect man who looked just like his father - so much so, in fact, that they could only be distinguished by their age?