What is the significance of "like a man's palm"?
Malbim (43): The rain will come only due to one man, i.e. Eliyahu. Then he knew that Shamayim will open via himself, so he told Achav to go home.
Why did he say to ascend to Achav?
Radak: Perhaps Achav had gone to a high place on the mountain to eat and drink.
What is the meaning of "Esor va'Red"?
Rashi: Tie (prepare) your chariot and descend from Har ha'Karmel to your house, lest rain make your journey difficult. Radak - there will be so much rain that you will not be able to travel.
Why is there a Hei at the end of "Ya'atzarcha"?
Radak: We find like this - "v'Hayah l'Os Al Yadechah" (Shemos 13:16), "ha'Nitzeves Imechah" (Shmuel I, 1:26), "v'Lo Ya'anuchah" (Yirmeyah 7:27).
