Why is he telling Eliyahu how Achav searched for him?
Malbim: If you want to see him, why did you hide until now? If you were waiting until he wants to see you - he asked all nations to find you. Surely you knew!
Eliyahu was in Tzarfas, Eretz Yisrael. Why did Achav not find him?
Radak: Perhaps the widow hid him and did not tell the people of her city, or Anshei Tzarfas hid him from Achav's Sheluchim.
Did Achav impose this oath on all nations of the world!
Radak citing Megilah 11a: Yes; he ruled b'Kipah (over the entire world) 1 .
Radak #1: He imposed oaths on all the nations around Eretz Yisrael. This was amidst love and request, not amidst fear of him.
Radak #2: He imposed oaths on merchants from all nations that came to Eretz Yisrael.
Radak: This is difficult. He did not rule even over Yehudah! He had wars; Aram took cities from him and put markets in Shomron (20:34)! Birkas Tziyon - perhaps he ruled b'Kipah, but then Aram amassed an army in order to rebel, and Achav feared them (20:4). (Or, perhaps initially he ruled b'Kipah, but then his kingdom was decimated due to the famine! - PF)
What is the meaning of "Ki Lo Yimtza'ekah"?
Rashi: The nation cannot find you.
