The keys of the sealing power spoken of in verse seven are the same as those held by the prophet Elijah. It was by the authority of these keys that he sealed the heavens for three and a half years, and by that same authority broke that seal and brought forth rain (see 1 Kings 17:1; 1 Kings 18:1, 45). Thus it was within his power to cause a famine to come upon his land. The authority to bring forth blessings is also the authority to withhold blessings.The power to bless is also the power to curse.
Of his servants in this day, the Lord has said that those who “go forth, bearing these tidings unto the inhabitants of the earth, to them is power given to seal both on earth and in heaven, the unbelieving and rebellious; yea, verily, to seal them up unto the day when the wrath of God shall be poured out upon the wicked without measure” (D&C 1:8-9). It was Elijah who conferred these keys upon Peter, James, and John on the Mount of Transfiguration (see Matthew 17:3; Teachings, p 158) and who also conferred them upon Joseph Smith and Oliver Cowdery (D&C 110:13-16).