Elijah Held Priesthood Keys

"The keys that Elijah held were the keys of the everlasting priesthood, the keys of the sealing power…and it is not confined to the living and it is not confined to the dead, but includes them both. These keys of the binding, or sealing power…are keys which make valid all the ordinances of the gospel. They pertain more especially to the work in the temples both for the living and for the dead… These keys hold the power to seal husbands and wives for eternity as well as for time. They hold the power to seal children to parents…by which the family organization is made intact forever…Through these keys the hearts of the children have turned to their fathers."
President Joseph Fielding Smith, Doctrines of Salvation, Vol. 2, pp. 112, 119