"The doctrine or sealing power of Elijah is as follows:—If you have power to seal on earth and in heaven, then we should be wise. The first thing you do, go and seal on earth your sons and daughters unto yourself, and yourself unto your fathers in eternal glory, and go ahead, and not go back, but use a little wisdom, and seal all you can, and when you get to heaven tell your Father that what you seal on earth should be sealed in heaven, according to his promise. I will walk through the gate of heaven and claim what I seal, and those that follow me and my counsel." (Joseph Smith, TPJS Section 6, p. 340)
Notice Joseph refers to others holding the sealing power, and gives himself as an example of one who holds it and seals.
"Joseph understood when the authority is given to any couple who's calling and election is sure, they were expected to use it to secure for themselves their kingdom." (Denver Snuffer, Beloved Enos, ch. 11, p. 147)