1 Kings 18:41  And Elijah said unto Ahab, Get thee up, eat and drink; for there is a sound of abundance of rain.
42  So Ahab went up to eat and to drink. And Elijah went up to the top of Carmel; and he cast himself down upon the earth, and put his face between his knees,
43  And said to his servant, Go up now, look toward the sea. And he went up, and looked, and said, There is nothing. And he said, Go again seven times.
44  And it came to pass at the seventh time, that he said, Behold, there ariseth a little cloud out of the sea, like a man's hand. And he said, Go up, say unto Ahab, Prepare thy chariot, and get thee down, that the rain stop thee not.
45  And it came to pass in the mean while, that the heaven was black with clouds and wind, and there was a great rain. And Ahab rode, and went to Jezreel.
46  And the hand of the LORD was on Elijah; and he girded up his loins, and ran before Ahab to the entrance of Jezreel.
A mystery:
Elijah, at the top of Carmel, told his servant to go up and look toward the sea. His servant did so and reported there was nothing. Seven times Elijah told his servant to go again. It was only then that the servant reported a little cloud out of the sea, like a man's hand.
What was Elijah doing the seven times? Verse 42 informs us that Elijah cast himself down upon the earth and put his face between his knees. So Elijah wasns't looking toward the sea. What then was happening? The passage doesn't explain. Could it be that Elihan was exercising his prophetic vision, and had seen the cloud like man's hand (the visible representation of the hand of God and was believing God for that cloud and that hand to manifest in the physical world. I think it is significant that when the servant saw the cloud like a man's hand, just two verses later, we read that the hand of the LORD was uo Elijah.
My conjecture is that while the servant saw the cloud appearing from beyond the horizon so, as though "out of the sea", what Elijah was really after was the hand of the Lord, of which the cloud was a token.
Why did it take so long? It looked as if during the seven times the servant went up to look, Elijah in his spirit was reaching out to the hand of God in the heavenies and pulling it towards earth in an operation of faith.
Could we do the same? Could we look to the Lord to show us what He wants to do, and then pull it towards us by faith, until, in the fullness of time, the thing the Lord showed in out spirit comes at last into physical reality?
It's not a conclusion we can draw by exegesis. Perhaps we can draw this conclusion by faith?