Elijah was a regular visitor at Rabbi's academy. He would slip in quietly, take his seat, and listen. One first-of-the-month he came in late, and Rabbi asked him what had kept him.
Elijah explained. "I have to wake up Abraham, Isaac, and Jacob one at a time. I pour water for each to wash his hands. I wait for each to finish his prayers. Then I help each return to his rest. Only then can I leave."
Rabbi asked the obvious question: "Why one at a time? Wake them all together and you would be finished in minutes."
Elijah's face went grave. "Because if the three patriarchs prayed at the same moment, their combined prayer would break the locks of heaven. It would force the Mashiach to come before his time" (Bava Metzia 85b).
Rabbi's eyes widened. "Are there any like them among us? Any living person whose prayer could match theirs?"
Elijah hesitated, then named Rabbi Cheyah and his sons. Rabbi proclaimed a public fast at once and invited Cheyah and his sons to lead. They stood at the amud and began the Shemoneh Esreh. When they reached the second blessing — "Thou restorest life to the dead" — the foundations of the world trembled. A voice rang out in heaven: "Who has told them the secret?"
Elijah was taken upstairs and struck sixty blows with a cudgel of fire. He came down like a fiery bear, charged into the assembly, and scattered the congregation before the prayer could finish.
Redemption is held back on purpose. Even Elijah may not hurry it.