"Ha'Ma'arah" implies that it was mentioned before this!
Rashi: This is "Nikras ha'Tzur" (Shemos 33:22) in which Moshe stood. Radak -Onkelos translated this 'b'Ma'aras Tinara.'
What was the question "Mah Lecha Fo Eliyahu"?
Radak: This was the beginning of the dialogue, to hear his answer, like people speak. "Mah Lecha ha'Yam Ki Sanus" (Tehilim 114:5) is for the sake of the answer, and also "Ei Hevel Achicha" (Bereishis 4:9), "ha'Ratzachta v'Gam Yarashta", "ha'Ra'isa Ki Nichna Achav" (below, 21:19, 29). Even though Hashem knows what is in people's hearts [He opens dialogues like this]. The same applies to "Ayeka" (Bereishis 3:9), "Mah Zeh b'Yadecha" (Shemos 4:2). Here, Hashem asked what are you doing here - why did you leave your place?
Malbim: A Navi should be among the nation, to rebuke and give Nevu'ah, and not isolate himself in the Midbar or mountains!
