Analogy:
A man owns a factory that produces widgets. The owner hires a foreman to actually run the operational aspects of the factory.
While the foreman is the one responsible for physically creating the widgets, it’s still the owner who decides how many widgets get made each day and in what colors and sizes.
“Holding the keys” may not mean that He physically does it, but rather that He makes the decisions as to when and where the rain falls.
After all, when Eliyahu held the keys, if he would have decided that it should rain, he wouldn’t have had to physically create the rain, but rather simply decree when/where it should fall.
The Wolf