D&C 110

The very purpose that the Lord commanded the Kirtland Temple to be built was -

"...the heavens were again opened unto us; and Moses appeared before us, and committed unto us the keys of the gathering of Israel from the four parts of the earth, and the leading of the ten tribes from the land of the north.

12 After this, Elias appeared, and committed the dispensation of the gospel of Abraham, saying that in us and our seed all generations after us should be blessed.

13 After this vision had closed, another great and glorious vision burst upon us; for Elijah the prophet, who was taken to heaven without tasting death, stood before us, and said:

14 Behold, the time has fully come, which was spoken of by the mouth of Malachi—testifying that he [Elijah] should be sent, before the great and dreadful day of the Lord come—

15 To turn the hearts of the fathers to the children, and the children to the fathers, lest the whole earth be smitten with a curse—

16 Therefore, the keys of this dispensation are committed into your hands; and by this ye may know that the great and dreadful day of the Lord is near, even at the doors."  (Doctrine and Covenants 110:11–16)

In my mind, the keys of the dispensation of the gospel of Abraham are all the temple ordinances, covenants, knowledge, and power that are essential for eternal increase.  The Keys brought by Elijah was the keys to bind on earth and in heaven...the sealing power and authority that validates all other priesthood works.